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Ye X, Wu M, Wang X, Dai X, Yu S, Tang X, Wang X, Zhong B. Sex separation by body color via a W-chromosome-linked transgene. Int J Biol Macromol 2023; 234:123649. [PMID: 36780960 DOI: 10.1016/j.ijbiomac.2023.123649] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 12/02/2022] [Accepted: 02/04/2023] [Indexed: 02/13/2023]
Abstract
Sex separation processes are important for commercial insect production and sterile insect techniques. Here, we describe the transgenic insertion of a DsRed expression cassette driven by the enhancer HR3 and strong promoter IE1 into the silkworm W chromosome as a dominant visible marker of sex separation. The obtained transgenic lines showed female-specific body color visible to the naked eye at the second- to fifth-instar larval, pupal and adult stages, and their performance traits were comparable to those of a nontransgenic practical silkworm variety. This strategy can greatly facilitate the sex separation of silkworms for male-only rearing and to obtain hybrids while avoiding sibling mating, and it can also be applied to the sex separation of other light-colored insects.
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Affiliation(s)
- Xiaogang Ye
- College of Animal Sciences, Zhejiang University, Hangzhou, PR China.
| | - Meiyu Wu
- College of Animal Sciences, Zhejiang University, Hangzhou, PR China
| | - Xinqiu Wang
- College of Animal Sciences, Zhejiang University, Hangzhou, PR China
| | - Xiangping Dai
- College of Animal Sciences, Zhejiang University, Hangzhou, PR China
| | - Shihua Yu
- College of Animal Sciences, Zhejiang University, Hangzhou, PR China
| | - Xiaoli Tang
- College of Animal Sciences, Zhejiang University, Hangzhou, PR China
| | - Xiaoxiao Wang
- College of Animal Sciences, Zhejiang University, Hangzhou, PR China
| | - Boxiong Zhong
- College of Animal Sciences, Zhejiang University, Hangzhou, PR China.
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2
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Gasparotto AE, Milani D, Martí E, Ferretti ABSM, Bardella VB, Hickmann F, Zrzavá M, Marec F, Cabral-de-Mello DC. A step forward in the genome characterization of the sugarcane borer, Diatraea saccharalis: karyotype analysis, sex chromosome system and repetitive DNAs through a cytogenomic approach. Chromosoma 2022; 131:253-267. [PMID: 36219241 DOI: 10.1007/s00412-022-00781-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 08/10/2022] [Accepted: 09/16/2022] [Indexed: 11/26/2022]
Abstract
Moths of the family Crambidae include a number of pests that cause economic losses to agricultural crops. Despite their economic importance, little is known about their genome architecture and chromosome evolution. Here, we characterized the chromosomes and repetitive DNA of the sugarcane borer Diatraea saccharalis using a combination of low-pass genome sequencing, bioinformatics, and cytogenetic methods, focusing on the sex chromosomes. Diploid chromosome numbers differed between the sexes, i.e., 2n = 33 in females and 2n = 34 in males. This difference was caused by the occurrence of a WZ1Z2 trivalent in female meiosis, indicating a multiple sex-chromosome system WZ1Z2/Z1Z1Z2Z2. A strong interstitial telomeric signal was observed on the W chromosome, indicating a fusion of the ancestral W chromosome with an autosome. Among repetitive DNAs, transposable elements (TEs) accounted for 39.18% (males) to 41.35% (females), while satDNAs accounted for only 0.214% (males) and 0.215% (females) of the genome. FISH mapping revealed different chromosomal organization of satDNAs, such as single localized clusters, spread repeats, and non-clustered repeats. Two TEs mapped by FISH were scattered. Although we found a slight enrichment of some satDNAs in the female genome, they were not differentially enriched on the W chromosome. However, we found enriched FISH signals for TEs on the W chromosome, suggesting their involvement in W chromosome degeneration and differentiation. These data shed light on karyotype and repetitive DNA dynamics due to multiple chromosome fusions in D. saccharalis, contribute to the understanding of genome structure in Lepidoptera and are important for future genomic studies.
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Affiliation(s)
- Ana E Gasparotto
- Departamento de Biologia Geral e Aplicada, Instituto de Biociências/IB, UNESP - Universidade Estadual Paulista, Rio Claro, SP, 13506-900, Brazil
| | - Diogo Milani
- Departamento de Biologia Geral e Aplicada, Instituto de Biociências/IB, UNESP - Universidade Estadual Paulista, Rio Claro, SP, 13506-900, Brazil
| | - Emiliano Martí
- Departamento de Biologia Geral e Aplicada, Instituto de Biociências/IB, UNESP - Universidade Estadual Paulista, Rio Claro, SP, 13506-900, Brazil
| | - Ana Beatriz S M Ferretti
- Departamento de Biologia Geral e Aplicada, Instituto de Biociências/IB, UNESP - Universidade Estadual Paulista, Rio Claro, SP, 13506-900, Brazil
| | - Vanessa B Bardella
- Departamento de Biologia Geral e Aplicada, Instituto de Biociências/IB, UNESP - Universidade Estadual Paulista, Rio Claro, SP, 13506-900, Brazil
| | - Frederico Hickmann
- Department of Entomology and Acarology, Luiz de Queiroz College of Agriculture, (USP/ESALQ), University of São Paulo, Piracicaba, SP, Brazil
| | - Magda Zrzavá
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, České Budějovice, Czech Republic
- Faculty of Science, University of South Bohemia, České Budějovice, Czech Republic
| | - František Marec
- Biology Centre of the Czech Academy of Sciences, Institute of Entomology, České Budějovice, Czech Republic
| | - Diogo C Cabral-de-Mello
- Departamento de Biologia Geral e Aplicada, Instituto de Biociências/IB, UNESP - Universidade Estadual Paulista, Rio Claro, SP, 13506-900, Brazil.
- Department of Experimental Biology, Genetics Area, University of Jaen, Paraje las Lagunillas s/n, 23071, Jaen, Spain.
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3
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Jiang S, Fu XW, Jiang SS, Yang XM, Zhao HY, Wu K. Effect of X-ray irradiation on development, flight, and reproduction of Spodoptera litura. Front Physiol 2022; 13:947848. [PMID: 35923242 PMCID: PMC9340251 DOI: 10.3389/fphys.2022.947848] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Accepted: 06/27/2022] [Indexed: 11/23/2022] Open
Abstract
Spodoptera litura is an omnivorous pest that has spread globally. Because irradiation sterilization technology has a great potential for control of S. litura, the effect of 25–150 Gy doses of X-rays on pupal survival, flight and reproductive variables of adult moths were analyzed in this research. The X-ray irradiation with the dose of 25–150 Gy significantly affected the reproductive ability of females. Irradiating male pupae with 25–150 Gy doses of X-rays had no effect on mating, life span, or flight ability of adult moths, but significantly reduced survival and fecundity of their offspring, and the sterility rate of the F1 generation was 52.65%–99.9%. The results of logistic curve fitting showed that the sterility impact was 84% at the most appropriate irradiation dose (71.26 Gy). The sterility control was 91% in an indoor mating competition experiment when the release ratio of irradiated males (75 Gy) to nonirradiated males reached 12.6:1. The effects of X-ray irradiation doses on biological variables of S. litura and the most effective release ratio determined here provide a theoretical foundation for using radiation sterilization technology to control S. litura.
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Affiliation(s)
- Shan Jiang
- College of Plant Protection, Shenyang Agricultural University, Shenyang, China
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Xiao-Wei Fu
- Henan Institute of Science and Technology, Xinxiang, China
| | - Shan-Shan Jiang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Xian-Ming Yang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Hui-Yuan Zhao
- Hebi Jiaduo Industry and Trade Co., Ltd., Hebi, China
| | - Kongming Wu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
- *Correspondence: Kongming Wu,
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Identification and Characterization of the Masculinizing Function of the Helicoverpa armigera Masc Gene. Int J Mol Sci 2021; 22:ijms22168650. [PMID: 34445352 PMCID: PMC8395511 DOI: 10.3390/ijms22168650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Revised: 08/08/2021] [Accepted: 08/09/2021] [Indexed: 11/17/2022] Open
Abstract
The Masculinizer (Masc) gene has been known to control sex development and dosage compensation in lepidopterans. However, it remains unclear whether its ortholog exists and plays the same roles in distantly related lepidopterans such as Helicoverpa armigera. To address this question, we cloned Masc from H. armigera (HaMasc), which contains all essential functional domains of BmMasc, albeit with less than 30% amino acid sequence identity with BmMasc. Genomic PCR and qPCR analyses showed that HaMasc is a Z chromosome-linked gene since its genomic content in males (ZZ) was two times greater than that in females (ZW). RT-PCR and RT-qPCR analyses revealed that HaMasc expression was sex- and stage-biased, with significantly more transcripts in males and eggs than in females and other stages. Transfection of a mixture of three siRNAs of HaMasc into a male embryonic cell line of H. armigera led to the appearance of female-specific mRNA splicing isoforms of H. armigeradoublesex (Hadsx), a downstream target gene of HaMasc in the H. armigera sex determination pathway. The knockdown of HaMasc, starting from the third instar larvae resulted in a shift of Hadsx splicing from male to female isoforms, smaller male pupa and testes, fewer but larger/longer spermatocytes and sperm bundles, delayed pupation and internal fusion of the testes and follicles. These data demonstrate that HaMasc functions as a masculinizing gene in the H. armigera sex-determination cascade.
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Aguirre C, Olivares N, Hinrichsen P. An Efficient Duplex PCR Method for Sex Identification of the European Grapevine Moth Lobesia botrana (Lepidoptera: Tortricidae) at Any Developmental Stage. JOURNAL OF ECONOMIC ENTOMOLOGY 2020; 113:2505-2510. [PMID: 32676656 DOI: 10.1093/jee/toaa155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2020] [Indexed: 06/11/2023]
Abstract
Many genetic studies in insects require sex identification of individuals in all developmental stages. The most common sex chromosome system in lepidopterans is WZ/ZZ; the W chromosome is present only in females. Based on two W chromosome-specific short sequences (CpW2 and CpW5) described in Cydia pomonella (L.) (Lepidoptera: Tortricidae), we identified homologous female-specific sequences in Lobesia botrana Den. & Schiff, a polyphagous and very harmful species present in Chile since 2008. From this starting point, we extended the sequence information using the inverse PCR method, identifying the first W-specific sequences described up to now for the moth. Finally, we developed a duplex PCR method for rapid and sensitive determination of sex in L. botrana from larva to adult. The method showed a detection limit of 1 pg of genomic DNA; a blind panel of samples exhibited exact correspondence with the morphological identification. These results will be very useful for studies requiring sex-specific analyses at any developmental stage, contributing also to the understanding of gene expression in the insect, as well as to the eventual development of control protocols against the moth, such as the development of genetic sexing strains for the implementation of the sterile insect technique.
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Affiliation(s)
- Carlos Aguirre
- Instituto de Investigaciones Agropecuarias, INIA-La Platina, Santiago, Chile
| | - Natalia Olivares
- Instituto de Investigaciones Agropecuarias, INIA-La Cruz, La Cruz, Quillota, Chile
| | - Patricio Hinrichsen
- Instituto de Investigaciones Agropecuarias, INIA-La Platina, Santiago, Chile
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Deng Z, Zhang Y, Zhang M, Huang J, Li C, Ni X, Li X. Characterization of the First W-Specific Protein-Coding Gene for Sex Identification in Helicoverpa armigera. Front Genet 2020; 11:649. [PMID: 32636875 PMCID: PMC7317607 DOI: 10.3389/fgene.2020.00649] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Accepted: 05/28/2020] [Indexed: 12/11/2022] Open
Abstract
Helicoverpa armigera is a globally-important crop pest with a WZ (female)/ZZ (male) sex chromosome system. The absence of discernible sexual dimorphism in its egg and larval stages makes it impossible to address any sex-related theoretical and applied questions before pupation unless a W-specific sequence marker is available for sex diagnosis. To this end, we used one pair of morphologically pre-sexed pupae to PCR-screen 17 non-transposon transcripts selected from 4855 W-linked candidate reads identified by mapping a publicly available egg transcriptome of both sexes to the male genome of this species and detected the read SRR1015458.67499 only in the female pupa. Subsequent PCR screenings of this read and the previously reported female-specific RAPD (random amplified polymorphic DNA) marker AF18 with ten more pairs of pre-sexed pupae and different annealing positions and/or temperatures as well as its co-occurrence with the female-specific transcript splicing isoforms of doublesex gene of H. armigera (Hadsx) and amplification and sequencing of their 5′ unknown flanking sequences in three additional pairs of pre-sexed pupae verified that SRR1015458.67499 is a single copy protein-coding gene unique to W chromosome (named GUW1) while AF18 is a multicopy MITE transposon located on various chromosomes. Test application of GUW1 as a marker to sex 30 neonates of H. armigera yielded a female/male ratio of 1.14: 1.00. Both GUW1 and Hadsx splicing isoforms assays revealed that the H. armigera embryo cell line QB-Ha-E-1 is a male cell line. Taken together, GUW1 is not only a reliable DNA marker for sexing all stages of H. armigera and its cell lines, but also represents the first W-specific protein-coding gene in lepidopterans.
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Affiliation(s)
- Zhongyuan Deng
- School of Agricultural Sciences, Zhengzhou University, Zhengzhou, China.,State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Yakun Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Min Zhang
- School of Agricultural Sciences, Zhengzhou University, Zhengzhou, China
| | - Jinyong Huang
- School of Agricultural Sciences, Zhengzhou University, Zhengzhou, China
| | - Changyou Li
- College of Plant Health and Medicine, Qingdao Agricultural University, Qingdao, China
| | - Xinzhi Ni
- Agricultural Research Service, U.S. Department of Agriculture, Crop Genetics and Breeding Research Unit, University of Georgia - Tifton Campus, Tifton, GA, United States
| | - Xianchun Li
- Department of Entomology and BIO5 Institute, University of Arizona, Tucson, AZ, United States
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7
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Activity and inactivity of moth sex chromosomes in somatic and meiotic cells. Chromosoma 2019; 128:533-545. [PMID: 31410566 DOI: 10.1007/s00412-019-00722-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 07/17/2019] [Accepted: 08/06/2019] [Indexed: 10/26/2022]
Abstract
Moths and butterflies (Lepidoptera) are the most species-rich group of animals with female heterogamety, females mostly having a WZ, males a ZZ sex chromosome constitution. We studied chromatin conformation, activity, and inactivity of the sex chromosomes in the flour moth Ephestia kuehniella and the silkworm Bombyx mori, using immunostaining with anti-H3K9me2/3, anti-RNA polymerase II, and fluoro-uridine (FU) labelling of nascent transcripts, with conventional widefield fluorescence microscopy and 'spatial structured illumination microscopy' (3D-SIM). The Z chromosome is euchromatic in somatic cells and throughout meiosis. It is transcriptionally active in somatic cells and in the postpachaytene stage of meiosis. The W chromosome in contrast is heterochromatic in somatic cells as well as in meiotic cells at pachytene, but euchromatic and transcriptionally active like all other chromosomes at postpachytene. As the W chromosomes are apparently devoid of protein-coding genes, their transcripts must be non-coding. We found no indication of 'meiotic sex chromosome inactivation' (MSCI) in the two species.
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8
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El-Samad LM, Radwan EH, Mokhamer EHM, Bakr NR. Aquatic beetles Cercyon unipunctatus as bioindicators of pollution in Lake Edku and Mariut, Egypt. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2019; 26:6557-6564. [PMID: 30628000 DOI: 10.1007/s11356-018-4016-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Accepted: 12/17/2018] [Indexed: 06/09/2023]
Abstract
The lakes of the North Delta give a rich and imperative territory for marine fish and its regeneration, and have dependably been major areas of fish creation in Egypt, 75% of the production was collected from them. As of late, many difficulties are confronting these lakes and prompt the exhaustion of fish production from them. The aim of the present study is to evaluate different inorganic pollutants in Coleopterons aquatic insect (Cercyon unipunctatus) taken from both Lake Edku and Mariut and also, to estimate their effect on oxidative stress markers and chromosomal aberrations. The average concentrations of heavy metals differ in the two locations. The concentration of (Pb, Cd, Fe, Co, Cu, Zn, and Mn) was significantly higher in water samples of Lake Mariut than those of Lake Edku. Also, the present work, showed the physical and chemical characters of the two lakes water. In the current study, the obtained results showed that there was a significant increase in (Pb, Cd, Fe, Co, Cu, Zn, and Mn) concentrations in C. unipunctatus tissues which were collected from Lake Mariut. The biochemical parameters of oxidative stress have been affected by the pollution in Lake Mariut water. Significant increases in the activity level of aspartate aminotransferase, alanine aminotransferase, and malondialdehyde concentration were recorded, while there were significant decreases in (total protein content, GSH content, and GPx activity). The result of chromosomal aberration test showed that there were different types of aberrations as binucleate cell, lagging chromosome, and abnormal distribution of chromosomes. The obtained data showed that C. unipunctatus highly affected by environmental stressors in water. So we suggest that these beetles could be a suitable monitor for ecotoxicological studies.
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Affiliation(s)
- Lamia M El-Samad
- Department of Zoology, Faculty of Science, Alexandria University, El Shatbi, Alexandria, 21511, Egypt
| | - Eman H Radwan
- Department of Zoology, Faculty of Science, Damanhour University, El Gmohoria street, El Beheira, Egypt.
| | | | - Nahed R Bakr
- Department of Zoology, Faculty of Science, Damanhour University, El Gmohoria street, El Beheira, Egypt
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KATSUMA S, KIUCHI T, KAWAMOTO M, FUJIMOTO T, SAHARA K. Unique sex determination system in the silkworm, Bombyx mori: current status and beyond. PROCEEDINGS OF THE JAPAN ACADEMY. SERIES B, PHYSICAL AND BIOLOGICAL SCIENCES 2018; 94:205-216. [PMID: 29760316 PMCID: PMC6021594 DOI: 10.2183/pjab.94.014] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Accepted: 02/19/2018] [Indexed: 06/02/2023]
Abstract
The silkworm Bombyx mori has been used for silk production for over 5,000 years. In addition to its contribution to sericulture, B. mori has played an important role in the field of genetics. Classical genetic studies revealed that a gene(s) with a strong feminizing activity is located on the W chromosome, but this W-linked feminizing gene, called Feminizer (Fem), had not been cloned despite more than 80 years of study. In 2014, we discovered that Fem is a precursor of a single W chromosome-derived PIWI-interacting RNA (piRNA). Fem-derived piRNA binds to PIWI protein, and this complex then cleaves the mRNA of the Z-linked Masculinizer (Masc) gene, which encodes a protein required for both masculinization and dosage compensation. These findings showed that the piRNA-mediated interaction between the two sex chromosomes is the primary signal for the sex determination cascade in B. mori. In this review, we summarize the history, current status, and perspective of studies on sex determination and related topics in B. mori.
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Affiliation(s)
- Susumu KATSUMA
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Takashi KIUCHI
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Munetaka KAWAMOTO
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Toshiaki FUJIMOTO
- Laboratory of Applied Entomology, Faculty of Agriculture, Iwate University, Iwate, Japan
| | - Ken SAHARA
- Laboratory of Applied Entomology, Faculty of Agriculture, Iwate University, Iwate, Japan
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10
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Kageyama D, Ohno M, Sasaki T, Yoshido A, Konagaya T, Jouraku A, Kuwazaki S, Kanamori H, Katayose Y, Narita S, Miyata M, Riegler M, Sahara K. Feminizing Wolbachia endosymbiont disrupts maternal sex chromosome inheritance in a butterfly species. Evol Lett 2017; 1:232-244. [PMID: 30283652 PMCID: PMC6121850 DOI: 10.1002/evl3.28] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 09/21/2017] [Accepted: 09/28/2017] [Indexed: 12/31/2022] Open
Abstract
Wolbachia is a maternally inherited ubiquitous endosymbiotic bacterium of arthropods that displays a diverse repertoire of host reproductive manipulations. For the first time, we demonstrate that Wolbachia manipulates sex chromosome inheritance in a sexually reproducing insect. Eurema mandarina butterfly females on Tanegashima Island, Japan, are infected with the wFem Wolbachia strain and produce all‐female offspring, while antibiotic treatment results in male offspring. Fluorescence in situ hybridization (FISH) revealed that wFem‐positive and wFem‐negative females have Z0 and WZ sex chromosome sets, respectively, demonstrating the predicted absence of the W chromosome in wFem‐infected lineages. Genomic quantitative polymerase chain reaction (qPCR) analysis showed that wFem‐positive females lay only Z0 eggs that carry a paternal Z, whereas females from lineages that are naturally wFem‐negative lay both WZ and ZZ eggs. In contrast, antibiotic treatment of adult wFem females resulted in the production of Z0 and ZZ eggs, suggesting that this Wolbachia strain can disrupt the maternal inheritance of Z chromosomes. Moreover, most male offspring produced by antibiotic‐treated wFem females had a ZZ karyotype, implying reduced survival of Z0 individuals in the absence of feminizing effects of Wolbachia. Antibiotic treatment of wFem‐infected larvae induced male‐specific splicing of the doublesex (dsx) gene transcript, causing an intersex phenotype. Thus, the absence of the female‐determining W chromosome in Z0 individuals is functionally compensated by Wolbachia‐mediated conversion of sex determination. We discuss how Wolbachia may manipulate the host chromosome inheritance and that Wolbachia may have acquired this coordinated dual mode of reproductive manipulation first by the evolution of female‐determining function and then cytoplasmically induced disruption of sex chromosome inheritance.
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Affiliation(s)
- Daisuke Kageyama
- Institute of Agrobiological Sciences National Agriculture and Food Research Organization Tsukuba Ibaraki 305-0854 Japan
| | - Mizuki Ohno
- Laboratory of Applied Entomology, Faculty of Agriculture Iwate University Morioka 020-8550 Japan
| | - Tatsushi Sasaki
- Laboratory of Applied Entomology, Faculty of Agriculture Iwate University Morioka 020-8550 Japan
| | - Atsuo Yoshido
- Laboratory of Applied Entomology, Faculty of Agriculture Iwate University Morioka 020-8550 Japan
| | - Tatsuro Konagaya
- Graduate School of Science Kyoto University Kyoto 606-8502 Japan
| | - Akiya Jouraku
- Institute of Agrobiological Sciences National Agriculture and Food Research Organization Tsukuba Ibaraki 305-0854 Japan
| | - Seigo Kuwazaki
- Institute of Agrobiological Sciences National Agriculture and Food Research Organization Tsukuba Ibaraki 305-0854 Japan
| | - Hiroyuki Kanamori
- Institute of Crop Science National Agriculture and Food Research Organization Tsukuba Ibaraki 305-0854 Japan
| | - Yuichi Katayose
- Institute of Crop Science National Agriculture and Food Research Organization Tsukuba Ibaraki 305-0854 Japan
| | - Satoko Narita
- Institute of Agrobiological Sciences National Agriculture and Food Research Organization Tsukuba Ibaraki 305-0854 Japan.,Tsukuba Primate Research Center National Institute of Biomedical Innovation Hachimandai Tsukuba Ibaraki 305-0843 Japan
| | - Mai Miyata
- Graduate School of Horticulture Chiba University Matsudo Chiba 271-8510 Japan
| | - Markus Riegler
- Hawkesbury Institute for the Environment Western Sydney University Penrith New South Wales 2751 Australia
| | - Ken Sahara
- Laboratory of Applied Entomology, Faculty of Agriculture Iwate University Morioka 020-8550 Japan
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11
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Fujii T, Abe H, Kawamoto M, Banno Y, Shimada T. Positional cloning of the sex-linked giant egg (Ge) locus in the silkworm, Bombyx mori. INSECT MOLECULAR BIOLOGY 2015; 24:213-221. [PMID: 25469867 DOI: 10.1111/imb.12150] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The giant egg (Ge) locus is a Z-linked mutation that leads to the production of large eggs. Cytological observations suggest that an unusual translocation of a large fragment of the W chromosome bearing a putative egg size-determining gene, Esd, gave rise to giant egg mutants. However, there is currently no molecular evidence confirming either a W-Z translocation or the presence of Esd on the W chromosome. To elucidate the origin of giant egg mutants, we performed positional cloning. We observed that the Bombyx mori. orthologue of the human Phytanoyl-CoA dioxygenase domain containing 1 gene (PHYHD1) is disrupted in giant egg mutants. PHYHD1 is highly conserved in eukaryotes and is predicted to be a Fe(II) and 2-oxoglutarate-dependent oxygenase. Exon skipping in one of the two available Ge mutants is probably caused by the insertion of a non-long terminal repeat transposon into intron 4 in the vicinity of the 5' splice site. Segmental duplication in Ge(2) , an independent allele, was caused by unequal recombination between short interspersed elements inserted into introns 3 and 5. Our results indicate that (1) Bombyx PHYHD1 is responsible for the Ge mutants and that (2) the Ge locus is unrelated to the W-linked putative Esd. To our knowledge, this is the first report describing the phenotypic defects caused by mutations in PHYHD1 orthologues.
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Affiliation(s)
- T Fujii
- Graduate School of Bioresource and Bioenvironmental Science, Kyushu University, Fukuoka, Japan; Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo-ku, Tokyo, Japan
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12
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Jiang L, Sun Q, Liu W, Guo H, Peng Z, Dang Y, Huang C, Zhao P, Xia Q. Postintegration stability of the silkworm piggyBac transposon. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2014; 50:18-23. [PMID: 24727025 DOI: 10.1016/j.ibmb.2014.03.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Revised: 03/03/2014] [Accepted: 03/14/2014] [Indexed: 06/03/2023]
Abstract
The piggyBac transposon is the most widely used vector for generating transgenic silkworms. The silkworm genome contains multiple piggyBac-like sequences that might influence the genetic stability of transgenic lines. To investigate the postintegration stability of piggyBac in silkworms, we used random insertion of the piggyBac [3 × p3 EGFP afm] vector to generate a W chromosome-linked transgenic silkworm, named W-T. Results of Southern blot and inverse PCR revealed the insertion of a single copy in the W chromosome of W-T at a standard TTAA insertion site. Investigation of 11 successive generations showed that all W-T females were EGFP positive and all males were EGFP negative; PCR revealed that the insertion site was unchanged in W-T offspring. These results suggested that endogenous piggyBac-like elements did not affect the stability of piggyBac inserted into the silkworm genome.
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Affiliation(s)
- Liang Jiang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, PR China; College of Biotechnology, Southwest University, Chongqing 400715, PR China
| | - Qiang Sun
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, PR China; College of Biotechnology, Southwest University, Chongqing 400715, PR China
| | - Weiqiang Liu
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, PR China; College of Biotechnology, Southwest University, Chongqing 400715, PR China
| | - Huizhen Guo
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, PR China; College of Biotechnology, Southwest University, Chongqing 400715, PR China
| | - Zhengwen Peng
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, PR China; College of Biotechnology, Southwest University, Chongqing 400715, PR China
| | - Yinghui Dang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, PR China; College of Biotechnology, Southwest University, Chongqing 400715, PR China
| | - Chunlin Huang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, PR China; College of Biotechnology, Southwest University, Chongqing 400715, PR China
| | - Ping Zhao
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, PR China; College of Biotechnology, Southwest University, Chongqing 400715, PR China
| | - Qingyou Xia
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, PR China; College of Biotechnology, Southwest University, Chongqing 400715, PR China.
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Ma S, Wang X, Fei J, Liu Y, Duan J, Wang F, Xu H, Zhao P, Xia Q. Genetic marking of sex using a W chromosome-linked transgene. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2013; 43:1079-1086. [PMID: 24036279 DOI: 10.1016/j.ibmb.2013.08.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2013] [Revised: 08/29/2013] [Accepted: 08/29/2013] [Indexed: 06/02/2023]
Abstract
Many species belonging to the order Lepidoptera are major pests in agriculture and arboriculture. The sterile insect technique (SIT) is an eco-friendly and highly efficient genetically targeted pest management approach. In many cases, it is preferable to release only sterile males in an SIT program, and efficient sexing strategies are crucial to the successful large-scale implementation of SIT. In the present study, we established 160 transgenic silkworm (Bombyx mori) lines to test the possibility of genetic sexing using a W chromosome-linked transgene, which is thought to be the best sexing strategy for lepidopteran species. One transgenic line with a female-specific expression pattern of reporter gene was obtained. The expression level of the W-linked transgene was comparable with autosomal insertions and was stable for 17 continuous generations. Molecular characterization showed this line contained a single copy of the reporter gene on the W chromosome, and the integration site was TTAG in contig W-BAC-522N19-C9. The feasibility of using a W chromosome-linked transgene demonstrated here and the possible improvements discussed will provide valuable information for other lepidopteran pests. The novel W chromosome-linked transgenic line established in this study will serve as an important resource for fundamental research with the silkworm B. mori.
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Affiliation(s)
- Sanyuan Ma
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400716, China
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14
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High-throughput sequencing of a single chromosome: a moth W chromosome. Chromosome Res 2013; 21:491-505. [PMID: 23949445 DOI: 10.1007/s10577-013-9376-6] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2013] [Revised: 07/23/2013] [Accepted: 07/23/2013] [Indexed: 10/26/2022]
Abstract
Y and W chromosomes have mostly been excluded from whole genome sequencing projects. Due to the high amount of repetitive sequences they are 'difficult' to assemble and therefore need special treatment in the form of, e.g. adapted assembly programs, a range of different libraries, and accurate maps, if possible. A minimum requirement for these approaches is pure template DNA. We therefore microdissected the W chromatin of highly polyploid cells from the flour moth, Ephestia kuehniella, and used Roche/454 and Sanger sequencing to generate 72.6 Mbp of DNA sequence. Nominal coverage was 4.3× of the 16.7 Mbp of W chromosomal DNA. We used these data to assess the genetic content of the W chromosome. This approach allowed us to determine constituent families of transposable elements, microsatellites, and recent insertion sites of mitochondrial DNA. However, no conventional protein-coding gene has yet been found. The sequence collection is a rich source for the definition of W-specific PCR markers and the reconstruction of W chromosome loci, as a step towards full reconstruction of the chromosome.
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15
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Yoshido A, Síchová J, Kubíčková S, Marec F, Sahara K. Rapid turnover of the W chromosome in geographical populations of wild silkmoths, Samia cynthia ssp. Chromosome Res 2013; 21:149-64. [PMID: 23515983 DOI: 10.1007/s10577-013-9344-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2013] [Revised: 02/25/2013] [Accepted: 02/26/2013] [Indexed: 11/24/2022]
Abstract
Our previous studies revealed a considerably high level of chromosomal polymorphism in wild silkmoths, Samia cynthia ssp. (Lepidoptera: Saturniidae). Geographical populations of this species complex differ in chromosome numbers and show derived sex chromosome systems including Z0/ZZ in S. cynthia ricini (2n = 27/28; Vietnam), neo-Wneo-Z/neo-Zneo-Z in S. cynthia walkeri (2n = 26/26; Sapporo, Hokkaido) and neo-WZ1Z2/Z1Z1Z2Z2 in S. cynthia subsp. indet. (2n = 25/26; Nagano, Honshu). In this study, we collected specimens of S. cynthia pryeri in Japanese islands Kyushu, Shikoku and Honshu, with an ancestral-like karyotype of 2n = 28 in both sexes and a WZ/ZZ sex chromosome system, except for one population, in which females have lost the W chromosome. However, the S. cynthia pryeri W chromosome showed a very unusual morphology: It was composed of a highly heterochromatic body, which remained condensed throughout the whole cell cycle and of a euchromatin-like "tail." We examined molecular composition of the W and neo-W chromosomes in S. cynthia subspecies by comparative genomic hybridisation and fluorescence in situ hybridisation with W chromosome painting probes prepared from laser-microdissected W chromatin of S. cynthia pryeri. These methods revealed that the molecular composition of highly heterochromatic part of the S. cynthia pryeri W chromosome is very different and lacks homology in the genomes of other subspecies, whereas the euchromatin-like part of the W chromosome corresponds to a heterochromatic part of the neo-W chromosomes in S. cynthia walkeri and S. cynthia subsp. indet. Our findings suggest that the curious WZ system of S. cynthia pryeri may represent an ancestral state of the Samia species complex but do not exclude an alternative hypothesis of its derived origin.
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Affiliation(s)
- Atsuo Yoshido
- Laboratory of Applied Molecular Entomology, Graduate School of Agriculture, Hokkaido University, Sapporo, Japan.
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16
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Linkage map of the peppered moth, Biston betularia (Lepidoptera, Geometridae): a model of industrial melanism. Heredity (Edinb) 2012; 110:283-95. [PMID: 23211790 DOI: 10.1038/hdy.2012.84] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
We have constructed a linkage map for the peppered moth (Biston betularia), the classical ecological genetics model of industrial melanism, aimed both at localizing the network of loci controlling melanism and making inferences about chromosome dynamics. The linkage map, which is based primarily on amplified fragment length polymorphisms (AFLPs) and genes, consists of 31 linkage groups (LGs; consistent with the karyotype). Comparison with the evolutionarily distant Bombyx mori suggests that the gene content of chromosomes is highly conserved. Gene order is conserved on the autosomes, but noticeably less so on the Z chromosome, as confirmed by physical mapping using bacterial artificial chromosome fluorescence in situ hybridization (BAC-FISH). Synteny mapping identified three pairs of B. betularia LGs (11/29, 23/30 and 24/31) as being orthologous to three B. mori chromosomes (11, 23 and 24, respectively). A similar finding in an outgroup moth (Plutella xylostella) indicates that the B. mori karyotype (n=28) is a phylogenetically derived state resulting from three chromosome fusions. As with other Lepidoptera, the B. betularia W chromosome consists largely of repetitive sequence, but exceptionally we found a W homolog of a Z-linked gene (laminin A), possibly resulting from ectopic recombination between the sex chromosomes. The B. betularia linkage map, featuring the network of known melanization genes, serves as a resource for melanism research in Lepidoptera. Moreover, its close resemblance to the ancestral lepidopteran karyotype (n=31) makes it a useful reference point for reconstructing chromosome dynamic events and ancestral genome architectures. Our study highlights the unusual evolutionary stability of lepidopteran autosomes; in contrast, higher rates of intrachromosomal rearrangements support a special role of the Z chromosome in adaptive evolution and speciation.
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Hara K, Fujii T, Suzuki Y, Sugano S, Shimada T, Katsuma S, Kawaoka S. Altered expression of testis-specific genes, piRNAs, and transposons in the silkworm ovary masculinized by a W chromosome mutation. BMC Genomics 2012; 13:119. [PMID: 22452797 PMCID: PMC3342102 DOI: 10.1186/1471-2164-13-119] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2012] [Accepted: 03/28/2012] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND In the silkworm, Bombyx mori, femaleness is strongly controlled by the female-specific W chromosome. Originally, it was presumed that the W chromosome encodes female-determining gene(s), accordingly called Fem. However, to date, neither Fem nor any protein-coding gene has been identified from the W chromosome. Instead, the W chromosome is occupied with numerous transposon-related sequences. Interestingly, the silkworm W chromosome is a source of female-enriched PIWI-interacting RNAs (piRNAs). piRNAs are small RNAs of 23-30 nucleotides in length, which are required for controlling transposon activity in animal gonads. A recent study has identified a novel mutant silkworm line called KG, whose mutation in the W chromosome causes severe female masculinization. However, the molecular nature of KG line has not been well characterized yet. RESULTS Here we molecularly characterize the KG line. Genomic PCR analyses using currently available W chromosome-specific PCR markers indicated that no large deletion existed in the KG W chromosome. Genetic analyses demonstrated that sib-crosses within the KG line suppressed masculinization. Masculinization reactivated when crossing KG females with wild type males. Importantly, the KG ovaries exhibited a significantly abnormal transcriptome. First, the KG ovaries misexpressed testis-specific genes. Second, a set of female-enriched piRNAs was downregulated in the KG ovaries. Third, several transposons were overexpressed in the KG ovaries. CONCLUSIONS Collectively, the mutation in the KG W chromosome causes broadly altered expression of testis-specific genes, piRNAs, and transposons. To our knowledge, this is the first study that describes a W chromosome mutant with such an intriguing phenotype.
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Affiliation(s)
- Kahori Hara
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Japan
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Kawaoka S, Kadota K, Arai Y, Suzuki Y, Fujii T, Abe H, Yasukochi Y, Mita K, Sugano S, Shimizu K, Tomari Y, Shimada T, Katsuma S. The silkworm W chromosome is a source of female-enriched piRNAs. RNA (NEW YORK, N.Y.) 2011; 17:2144-51. [PMID: 22020973 PMCID: PMC3222127 DOI: 10.1261/rna.027565.111] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
In the silkworm, Bombyx mori, the W chromosome plays a dominant role in female determination. However, neither protein-coding genes nor transcripts have so far been isolated from the W chromosome. Instead, a large amount of functional transposable elements and their remnants are accumulated on the W chromosome. PIWI-interacting RNAs (piRNAs) are 23-30-nt-long small RNAs that potentially act as sequence-specific guides for PIWI proteins to silence transposon activity in animal gonads. In this study, by comparing ovary- and testis-derived piRNAs, we identified numerous female-enriched piRNAs. Our data indicated that female-enriched piRNAs are derived from the W chromosome. Moreover, comparative analyses on piRNA profiles from a series of W chromosome mutant strains revealed a striking enrichment of a specific set of transposon-derived piRNAs in the putative sex-determining region. Collectively, we revealed the nature of the silkworm W chromosome as a source of piRNAs.
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Affiliation(s)
- Shinpei Kawaoka
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan
| | - Koji Kadota
- Agricultural Bioinformatics Research Unit, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan
| | - Yuji Arai
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan
| | - Yutaka Suzuki
- Department of Medical Genome Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Tokyo 108-8639, Japan
| | - Tsuguru Fujii
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan
| | - Hiroaki Abe
- Division of Agriscience and Bioscience, Institute of Symbiotic Science and Technology, Tokyo University of Agriculture and Technology, Tokyo 183-8509, Japan
| | - Yuji Yasukochi
- National Institute of Agrobiological Sciences, Tsukuba 305-8634, Japan
| | - Kazuei Mita
- National Institute of Agrobiological Sciences, Tsukuba 305-8634, Japan
| | - Sumio Sugano
- Department of Medical Genome Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Tokyo 108-8639, Japan
| | - Kentaro Shimizu
- Agricultural Bioinformatics Research Unit, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan
| | - Yukihide Tomari
- Institute of Molecular and Cellular Biosciences, and Department of Medical Genome Sciences, Graduate School of Frontier Sciences, The University of Tokyo, Tokyo 113-0032, Japan
| | - Toru Shimada
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan
- Agricultural Bioinformatics Research Unit, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan
| | - Susumu Katsuma
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan
- Corresponding author.E-mail .
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A rearrangement of the Z chromosome topology influences the sex-linked gene display in the European corn borer, Ostrinia nubilalis. Mol Genet Genomics 2011; 286:37-56. [DOI: 10.1007/s00438-011-0624-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2010] [Accepted: 04/16/2011] [Indexed: 12/22/2022]
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Fujii T, Abe H, Shimada T. Molecular analysis of sex chromosome-linked mutants in the silkworm Bombyx mori. J Genet 2011; 89:365-74. [PMID: 20877003 DOI: 10.1007/s12041-010-0048-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
In Bombyx mori, the W chromosome determines the female sex. A few W chromosome-linked mutations that cause masculinization of the female genitalia have been found. In female antennae of a recently isolated mutant, both female-type and male-type Bmdsx mRNAs were expressed, and BmOr1 (bombykol receptor) and BmOr3 (bombykal receptor), which are predominantly expressed in the antennae of male moths, were expressed about 50 times more abundantly in the antennae of mutant females than in those of normal females. These mutants are valuable resources for the molecular analysis of the sexdetermination system. Besides the Fem gene, the quantitative egg size-determining gene Esd is thought to be present on the W chromosome, based on the observation that ZWW triploid moths produce larger eggs than ZZW triploids. The most recently updated B. mori genome assembly comprises 20.5 Mb of Z chromosome sequence. Using these sequence data, responsible genes or candidate genes for four Z-linked mutants have been reported. The od (distinct oily) and spli (soft and pliable) are caused by mutation in BmBLOS2 and Bmacj6, respectively. Bmap is a candidate gene for Vg (vestigial). Similarly, Bmprm is a candidate gene for Md (muscle dystrophy), causing abnormal development of indirect flight muscle.
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Affiliation(s)
- Tsuguru Fujii
- Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan
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Miyashita T, Araki H, Hoshino Y. Ploidy distribution and DNA content variations of Lonicera caerulea (caprifoliaceae) in Japan. JOURNAL OF PLANT RESEARCH 2011; 124:1-9. [PMID: 20422248 DOI: 10.1007/s10265-010-0341-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2009] [Accepted: 03/14/2010] [Indexed: 05/29/2023]
Abstract
Ploidy level and geographical distribution were investigated in Japanese Lonicera caerulea L. Flow cytometric analysis revealed the presence of DNA diploid and DNA tetraploid plants in Japan. Chromosome observation confirmed that diploid and tetraploid plants showed 2n = 2x = 8 and 2n =4x = 36, respectively. The DNA diploid populations were found only in lowland mires, Betsukai, Bekanbeushi, Kushiro and Kiritappu located in eastern Hokkaido. On the other hand, DNA tetraploid populations were distributed in a wide area of Hokkaido, and mainland of Japan. The habitats of DNA tetraploid plants were lowland to alpine region. The DNA content measurement with flow cytometry revealed significant differences in the relative DNA contents among DNA tetraploid populations. The relative DNA content within DNA tetraploid populations varied 1.157-fold at maximum, and might correlate with altitude indicating that DNA contents were smaller as altitude increases. The wide area of distribution in various environments of DNA tetraploid plants suggested the adaptability of the tetraploid plants. Although diploid and tetraploid populations were found, no triploid was detected, indicating crossing difficulty between diploid and tetraploid as confirmed by crossing experiment.
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Affiliation(s)
- Tomomi Miyashita
- Division of Biosphere Science, Graduate School of Environmental Science, Hokkaido University, Kita 11, Nishi 10, Kita-Ku, Sapporo, 060-0811, Japan
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Yoshido A, Sahara K, Marec F, Matsuda Y. Step-by-step evolution of neo-sex chromosomes in geographical populations of wild silkmoths, Samia cynthia ssp. Heredity (Edinb) 2010; 106:614-24. [PMID: 20668432 DOI: 10.1038/hdy.2010.94] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Geographical subspecies of wild silkmoths, Samia cynthia ssp. (Lepidoptera: Saturniidae), differ considerably in sex chromosome constitution owing to sex chromosome fusions with autosomes, which leads to variation in chromosome numbers. We cloned S. cynthia orthologues of 16 Bombyx mori genes and mapped them to chromosome spreads of S. cynthia subspecies by fluorescence in situ hybridization (FISH) to determine the origin of S. cynthia neo-sex chromosomes. FISH mapping revealed that the Z chromosome and chromosome 12 of B. mori correspond to the Z chromosome and an autosome (A₁) of S. c. ricini (Vietnam population, 2n=27, Z0 in female moths), respectively. B. mori chromosome 11 corresponds partly to another autosome (A₂) and partly to a chromosome carrying nucleolar organizer region (NOR) of this subspecies. The NOR chromosome of S. c. ricini is also partly homologous to B. mori chromosome 24. Furthermore, our results revealed that two A₁ homologues each fused with the W and Z chromosomes in a common ancestor of both Japanese subspecies S. c. walkeri (Sapporo population, 2n=26, neo-Wneo-Z) and S. cynthia subsp. indet. (Nagano population, 2n=25, neo-WZ₁Z₂). One homologue, corresponding to the A₂ autosome in S. c. ricini and S. c. walkeri, fused with the W chromosome in S. cynthia subsp. indet. Consequently, the other homologue became a Z₂ chromosome. These results clearly showed a step-by-step evolution of the neo-sex chromosomes by repeated autosome-sex chromosome fusions. We suggest that the rearrangements of sex chromosomes may facilitate divergence of S. cynthia subspecies towards speciation.
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Affiliation(s)
- A Yoshido
- Laboratory of Applied Molecular Entomology, Graduate School of Agriculture, Hokkaido University, Kita-ku, Sapporo, Japan.
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24
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Sreekumar S, Kadono-Okuda K, Nagayasu KI, Hara W. Identification of 2chromosome region translocated onto the W chromosome by RFLP with EST-cDNA clones in the Gensei-kouken strains of the mulberry silkworm, Bombyx mori L. Genet Mol Biol 2010; 33:27-35. [PMID: 21637601 PMCID: PMC3036075 DOI: 10.1590/s1415-47572009005000105] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2009] [Accepted: 07/29/2009] [Indexed: 11/21/2022] Open
Abstract
In silkworms, sex-limited strains are either obtained spontaneously or induced by X-rays or gamma rays. When a fragment of an autosome carrying a dominant allele of those genes responsible for certain characters is translocated onto a W chromosome, the female of the successive generations will express these phenotypic characters and sex discrimination can be facilitated. Gensei-kouken strains are sex-limited strains of silkworms developed by irradiating the pupae with gamma rays, by which a portion of the second chromosome is translocated onto the W chromosome. In these improved strains, the females are yellow-blooded and spin yellow cocoons. By using the EST-cDNA clones mapped on the Z chromosome, we identified the sex according to the polymorphic banding pattern or intensity of the signals. Furthermore, by using the clones on the second chromosome, the region of the second chromosome translocated onto the W chromosome was also defined. In both the A95 and A 96 strains selected for the present study, only the mid-portion of the second chromosome was translocated. The differences in length of the fragments translocated in these strains are discussed.
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Affiliation(s)
- Sivaramakurup Sreekumar
- Insect Genome Laboratory, National Institute of Agrobiological Sciences, Tsukuba, Ibaraki Japan
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25
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Evolutionary dynamics of rDNA clusters on chromosomes of moths and butterflies (Lepidoptera). Genetica 2009; 138:343-354. [PMID: 19921441 DOI: 10.1007/s10709-009-9424-5] [Citation(s) in RCA: 92] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2009] [Accepted: 11/03/2009] [Indexed: 01/05/2023]
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Extensive conserved synteny of genes between the karyotypes of Manduca sexta and Bombyx mori revealed by BAC-FISH mapping. PLoS One 2009; 4:e7465. [PMID: 19829706 PMCID: PMC2759293 DOI: 10.1371/journal.pone.0007465] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2009] [Accepted: 09/23/2009] [Indexed: 12/02/2022] Open
Abstract
Background Genome sequencing projects have been completed for several species representing four highly diverged holometabolous insect orders, Diptera, Hymenoptera, Coleoptera, and Lepidoptera. The striking evolutionary diversity of insects argues a need for efficient methods to apply genome information from such models to genetically uncharacterized species. Constructing conserved synteny maps plays a crucial role in this task. Here, we demonstrate the use of fluorescence in situ hybridization with bacterial artificial chromosome probes as a powerful tool for physical mapping of genes and comparative genome analysis in Lepidoptera, which have numerous and morphologically uniform holokinetic chromosomes. Methodology/Principal Findings We isolated 214 clones containing 159 orthologs of well conserved single-copy genes of a sequenced lepidopteran model, the silkworm, Bombyx mori, from a BAC library of a sphingid with an unexplored genome, the tobacco hornworm, Manduca sexta. We then constructed a BAC-FISH karyotype identifying all 28 chromosomes of M. sexta by mapping 124 loci using the corresponding BAC clones. BAC probes from three M. sexta chromosomes also generated clear signals on the corresponding chromosomes of the convolvulus hawk moth, Agrius convolvuli, which belongs to the same subfamily, Sphinginae, as M. sexta. Conclusions/Significance Comparison of the M. sexta BAC physical map with the linkage map and genome sequence of B. mori pointed to extensive conserved synteny including conserved gene order in most chromosomes. Only a few rearrangements, including three inversions, three translocations, and two fission/fusion events were estimated to have occurred after the divergence of Bombycidae and Sphingidae. These results add to accumulating evidence for the stability of lepidopteran genomes. Generating signals on A. convolvuli chromosomes using heterologous M. sexta probes demonstrated that BAC-FISH with orthologous sequences can be used for karyotyping a wide range of related and genetically uncharacterized species, significantly extending the ability to develop synteny maps for comparative and functional genomics.
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Shibata F, Sahara K, Naito Y, Yasukochi Y. Reprobing multicolor FISH preparations in lepidopteran chromosome. Zoolog Sci 2009; 26:187-90. [PMID: 19341338 DOI: 10.2108/zsj.26.187] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Multicolor fluorescence in-situ hybridization (FISH) and subsequent reprobing of chromosome preparations increase the number of chromosomes and/or anchor loci on the chromosomes simultaneously identified. Reprobing techniques have been widely applied to chromosomes of vertebrates and plants. We have developed a novel reprobing protocol that utilizes multicolor FISH and bacterial artificial chromosome (BAC) probes to examine chromosome preparations in a model lepidopteran species, the silkworm, Bombyx mori. With standard two-color BAC-FISH, routinely used to map genes on B. mori chromosomes, we could localize only two probes on one preparation, whereas our new protocol combining five-color BAC-FISH and preparation reprobing enabled us to simultaneously map 10 probes, as demonstrated with the Bombyx Z chromosome. The improved BAC-FISH technique will facilitate karyotyping and synteny analysis in Lepidoptera.
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Affiliation(s)
- Fukashi Shibata
- Laboratory of Applied Molecular Entomology, Research Institute of Agriculture, Hokkaido University, Sapporo 060-8589, Japan
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Cytogenetic characterization and AFLP-based genetic linkage mapping for the butterfly Bicyclus anynana, covering all 28 karyotyped chromosomes. PLoS One 2008; 3:e3882. [PMID: 19060955 PMCID: PMC2588656 DOI: 10.1371/journal.pone.0003882] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2008] [Accepted: 11/13/2008] [Indexed: 11/19/2022] Open
Abstract
Background The chromosome characteristics of the butterfly Bicyclus anynana, have received little attention, despite the scientific importance of this species. This study presents the characterization of chromosomes in this species by means of cytogenetic analysis and linkage mapping. Methodology/Principal Findings Physical genomic features in the butterfly B. anynana were examined by karyotype analysis and construction of a linkage map. Lepidoptera possess a female heterogametic W-Z sex chromosome system. The WZ-bivalent in pachytene oocytes of B. anynana consists of an abnormally small, heterochromatic W-chromosome with the Z-chromosome wrapped around it. Accordingly, the W-body in interphase nuclei is much smaller than usual in Lepidoptera. This suggests an intermediate stage in the process of secondary loss of the W-chromosome to a ZZ/Z sex determination system. Two nucleoli are present in the pachytene stage associated with an autosome and the WZ-bivalent respectively. Chromosome counts confirmed a haploid number of n = 28. Linkage mapping had to take account of absence of crossing-over in females, and of our use of a full-sib crossing design. We developed a new method to determine and exclude the non-recombinant uninformative female inherited component in offspring. The linkage map was constructed using a novel approach that uses exclusively JOINMAP-software for Lepidoptera linkage mapping. This approach simplifies the mapping procedure, avoids over-estimation of mapping distance and increases the reliability of relative marker positions. A total of 347 AFLP markers, 9 microsatellites and one single-copy nuclear gene covered all 28 chromosomes, with a mapping distance of 1354 cM. Conserved synteny of Tpi on the Z-chromosome in Lepidoptera was confirmed for B. anynana. The results are discussed in relation to other mapping studies in Lepidoptera. Conclusions/Significance This study adds to the knowledge of chromosome structure and evolution of an intensively studied organism. On a broader scale it provides an insight in Lepidoptera sex chromosome evolution and it proposes a simpler and more reliable method of linkage mapping than used for Lepidoptera to date.
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Song F, Chang P, Zhang P, Yi F, Ma Y, Lu C, Banno Y, Fujii H. Chromosomal localization of silkworm (Bombyx mori) sericin gene 1 and chymotrypsin inhibitor 13 using fluorescence in situ hybridization. SCIENCE IN CHINA. SERIES C, LIFE SCIENCES 2008; 51:133-139. [PMID: 18239891 DOI: 10.1007/s11427-008-0025-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2007] [Accepted: 12/06/2007] [Indexed: 05/25/2023]
Abstract
The chromosomal locations of two single-copy genes, Ser-1 and CI-13, in silkworm (Bombyx mori) were detected at the molecular cytogenetics level by fluorescence in situ hybridization in the study. The results showed that Ser-1 is located near the distal end of the 11th linkage group, relatively at the 12.5+/-1.4 position in pachytene; and that CI-13 has been mapped near the distal end of the 2nd linkage group, relatively at the 8.2+/-1.2 position in pachytene. Furthermore, their location model map-FISH map on silkworm chromosome was drawn. The FISH technique and its application to silkworm are also discussed in this paper.
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Affiliation(s)
- FangZhou Song
- Department of Molecular Biology, Chongqing Medical University, Chongqing 400016, China.
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30
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Traut W, Sahara K, Marec F. Sex Chromosomes and Sex Determination in Lepidoptera. Sex Dev 2008; 1:332-46. [DOI: 10.1159/000111765] [Citation(s) in RCA: 133] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2007] [Accepted: 10/24/2007] [Indexed: 11/19/2022] Open
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31
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Molecular divergence of the W chromosomes in pyralid moths (Lepidoptera). Chromosome Res 2007; 15:917-30. [PMID: 17985203 DOI: 10.1007/s10577-007-1173-7] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2007] [Revised: 09/08/2007] [Accepted: 09/08/2007] [Indexed: 10/22/2022]
Abstract
Most Lepidoptera have a WZ/ZZ sex chromosome system. We compared structure of W chromosomes in four representatives of the family Pyralidae--Ephestia kuehniella, Cadra cautella, Plodia interpunctella, and Galleria mellonella--tracing pachytene bivalents which provide much higher resolution than metaphase chromosomes. In each species, we prepared a W-chromosome painting probe from laser-microdissected W-chromatin of female polyploid nuclei. The Ephestia W-probe was cross-hybridized to chromosomes of the other pyralids to detect common parts of their W chromosomes, while the species-specific W-probes identified the respective W chromosome. This so-called Zoo-FISH revealed a partial homology of W-chromosome regions between E. kuehniella and two other pyralids, C. cautella and P. interpunctella, but almost no homology with G. mellonella. The results were consistent with phylogenetic relationships between the species. We also performed comparative genomic hybridization, which indicated that the W chromosome of C. cautella is composed mainly of repetitive DNA common to both sexes but accumulated in the W chromosome, whereas E. kuehniella, P. interpunctella, and G. mellonella W chromosomes also possess a large amount of female specific DNA sequences, but differently organized. Our results support the hypothesis of the accelerated molecular divergence of the lepidopteran W chromosomes in the absence of meiotic recombination.
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Sahara K, Yoshido A, Marec F, Fuková I, Zhang HB, Wu CC, Goldsmith MR, Yasukochi Y. Conserved synteny of genes between chromosome 15 of Bombyx mori and a chromosome of Manduca sexta shown by five-color BAC-FISH. Genome 2007; 50:1061-5. [DOI: 10.1139/g07-082] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The successful assignment of the existing genetic linkage groups (LGs) to individual chromosomes and the second-generation linkage map obtained by mapping a large number of bacterial artificial chromosome (BAC) contigs in the silkworm, Bombyx mori , together with public nucleotide sequence databases, offer a powerful tool for the study of synteny between karyotypes of B. mori and other lepidopteran species. Conserved synteny of genes between particular chromosomes can be identified by comparatively mapping orthologous genes of the corresponding linkage groups with the help of BAC-FISH (fluorescent in situ hybridization). This technique was established in B. mori for 2 differently labeled BAC probes simultaneously hybridized to pachytene bivalents. To achieve higher-throughput comparative mapping using BAC-FISH in Lepidoptera, we developed a protocol for five-color BAC-FISH, which allowed us to map simultaneously 6 different BAC probes to chromosome 15 in B. mori. We identified orthologs of 6 B. mori LG15 genes (RpP0, RpS8, eIF3, RpL7A, RpS23, and Hsc70) for the tobacco hornworm, Manduca sexta , and selected the ortholog-containing BAC clones from an M. sexta BAC library. All 6 M. sexta BAC clones hybridized to a single M. sexta bivalent in pachytene spermatocytes. Thus, we have confirmed the conserved synteny between the B. mori chromosome 15 and the corresponding M. sexta chromosome (hence provisionally termed chromosome 15).
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Affiliation(s)
- Ken Sahara
- Laboratory of Applied Molecular Entomology, Research Institute of Agriculture, Hokkaido University, N9, W9, Kita-ku, Sapporo 060-8589, Japan
- Laboratory of Animal Cytogenetics, Creative Research Initiative “Sosei”, Hokkaido University, N10, W8, Kita-ku, Sapporo 060-0810, Japan
- Biology Centre ASCR, Institute of Entomology and Faculty of Science, University of South Bohemia, Branišovská 31, CZ-370 05 České Budějovice, Czech Republic
- Department of Soil and Crop Sciences, Texas A&M University, College Station, TX 77843, USA
- Department of Biological Sciences, University of Rhode Island, Kingston, RI 02881, USA
| | - Atsuo Yoshido
- Laboratory of Applied Molecular Entomology, Research Institute of Agriculture, Hokkaido University, N9, W9, Kita-ku, Sapporo 060-8589, Japan
- Laboratory of Animal Cytogenetics, Creative Research Initiative “Sosei”, Hokkaido University, N10, W8, Kita-ku, Sapporo 060-0810, Japan
- Biology Centre ASCR, Institute of Entomology and Faculty of Science, University of South Bohemia, Branišovská 31, CZ-370 05 České Budějovice, Czech Republic
- Department of Soil and Crop Sciences, Texas A&M University, College Station, TX 77843, USA
- Department of Biological Sciences, University of Rhode Island, Kingston, RI 02881, USA
| | - František Marec
- Laboratory of Applied Molecular Entomology, Research Institute of Agriculture, Hokkaido University, N9, W9, Kita-ku, Sapporo 060-8589, Japan
- Laboratory of Animal Cytogenetics, Creative Research Initiative “Sosei”, Hokkaido University, N10, W8, Kita-ku, Sapporo 060-0810, Japan
- Biology Centre ASCR, Institute of Entomology and Faculty of Science, University of South Bohemia, Branišovská 31, CZ-370 05 České Budějovice, Czech Republic
- Department of Soil and Crop Sciences, Texas A&M University, College Station, TX 77843, USA
- Department of Biological Sciences, University of Rhode Island, Kingston, RI 02881, USA
| | - Iva Fuková
- Laboratory of Applied Molecular Entomology, Research Institute of Agriculture, Hokkaido University, N9, W9, Kita-ku, Sapporo 060-8589, Japan
- Laboratory of Animal Cytogenetics, Creative Research Initiative “Sosei”, Hokkaido University, N10, W8, Kita-ku, Sapporo 060-0810, Japan
- Biology Centre ASCR, Institute of Entomology and Faculty of Science, University of South Bohemia, Branišovská 31, CZ-370 05 České Budějovice, Czech Republic
- Department of Soil and Crop Sciences, Texas A&M University, College Station, TX 77843, USA
- Department of Biological Sciences, University of Rhode Island, Kingston, RI 02881, USA
| | - Hong-Bin Zhang
- Laboratory of Applied Molecular Entomology, Research Institute of Agriculture, Hokkaido University, N9, W9, Kita-ku, Sapporo 060-8589, Japan
- Laboratory of Animal Cytogenetics, Creative Research Initiative “Sosei”, Hokkaido University, N10, W8, Kita-ku, Sapporo 060-0810, Japan
- Biology Centre ASCR, Institute of Entomology and Faculty of Science, University of South Bohemia, Branišovská 31, CZ-370 05 České Budějovice, Czech Republic
- Department of Soil and Crop Sciences, Texas A&M University, College Station, TX 77843, USA
- Department of Biological Sciences, University of Rhode Island, Kingston, RI 02881, USA
| | - Cheng-Cang Wu
- Laboratory of Applied Molecular Entomology, Research Institute of Agriculture, Hokkaido University, N9, W9, Kita-ku, Sapporo 060-8589, Japan
- Laboratory of Animal Cytogenetics, Creative Research Initiative “Sosei”, Hokkaido University, N10, W8, Kita-ku, Sapporo 060-0810, Japan
- Biology Centre ASCR, Institute of Entomology and Faculty of Science, University of South Bohemia, Branišovská 31, CZ-370 05 České Budějovice, Czech Republic
- Department of Soil and Crop Sciences, Texas A&M University, College Station, TX 77843, USA
- Department of Biological Sciences, University of Rhode Island, Kingston, RI 02881, USA
| | - Marian R. Goldsmith
- Laboratory of Applied Molecular Entomology, Research Institute of Agriculture, Hokkaido University, N9, W9, Kita-ku, Sapporo 060-8589, Japan
- Laboratory of Animal Cytogenetics, Creative Research Initiative “Sosei”, Hokkaido University, N10, W8, Kita-ku, Sapporo 060-0810, Japan
- Biology Centre ASCR, Institute of Entomology and Faculty of Science, University of South Bohemia, Branišovská 31, CZ-370 05 České Budějovice, Czech Republic
- Department of Soil and Crop Sciences, Texas A&M University, College Station, TX 77843, USA
- Department of Biological Sciences, University of Rhode Island, Kingston, RI 02881, USA
| | - Yuji Yasukochi
- Laboratory of Applied Molecular Entomology, Research Institute of Agriculture, Hokkaido University, N9, W9, Kita-ku, Sapporo 060-8589, Japan
- Laboratory of Animal Cytogenetics, Creative Research Initiative “Sosei”, Hokkaido University, N10, W8, Kita-ku, Sapporo 060-0810, Japan
- Biology Centre ASCR, Institute of Entomology and Faculty of Science, University of South Bohemia, Branišovská 31, CZ-370 05 České Budějovice, Czech Republic
- Department of Soil and Crop Sciences, Texas A&M University, College Station, TX 77843, USA
- Department of Biological Sciences, University of Rhode Island, Kingston, RI 02881, USA
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Abe H, Fujii T, Tanaka N, Yokoyama T, Kakehashi H, Ajimura M, Mita K, Banno Y, Yasukochi Y, Oshiki T, Nenoi M, Ishikawa T, Shimada T. Identification of the female-determining region of the W chromosome in Bombyx mori. Genetica 2007; 133:269-82. [PMID: 17901928 DOI: 10.1007/s10709-007-9210-1] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2007] [Accepted: 09/08/2007] [Indexed: 10/22/2022]
Abstract
The W chromosome of the silkworm Bombyx mori is devoid of functional genes, except for the putative female-determining gene (Fem). To localize Fem, we investigated the presence of W-specific DNA markers on strains in which an autosomal fragment containing dominant marker genes was attached to the W chromosome. We produced new W-chromosomal fragments from the existing Zebra-W strain (T(W;3)Ze chromosome) by X-irradiation, and then carried out deletion mapping of these and sex-limited yellow cocoon strains (T(W;2)Y-Chu, -Abe and -Ban types) from different Japanese stock centers. Of 12 RAPD markers identified in the normal W chromosomes of most silkworm strains in Japan, the newly irradiated W(B-YL-YS)Ze chromosome contained three, the T(W;2)Y-Chu chromosome contained six, and the T(W;2)Y-Abe and -Ban chromosomes contained only one (W-Rikishi). To investigate the ability of the reduced W-chromosome translocation fragments to form heterochromatin bodies, which are found in nuclei of normal adult female sucking stomachs, we examined cells of the normal type p50 strain and the T(W;2)Y-Chu and -Abe strains. A single sex heterochromatin body was found in nuclei of p50 females, whereas we detected only small sex heterochromatin bodies in the T(W;2)Y-Chu strain and no sex heterochromatin body in the T(W;2)Y-Abe strain. Since adult females of all strains were normal and fertile, we conclude that only extremely limited region, containing the W-Rikishi RAPD sequence of the W chromosome, is required to determine femaleness. Based on a comparison of the normal W-chromosome and 7 translocation and W-deletion strains we present a map of Fem relative to the 12 W-specific RAPD markers.
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Affiliation(s)
- H Abe
- Department of Biological Production, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Saiwai-cho, 3-5-8 Fuchu, Tokyo 183-8509, Japan.
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Fuková I, Nguyen P, Marec F. Codling moth cytogenetics: karyotype, chromosomal location of rDNA, and molecular differentiation of sex chromosomes. Genome 2007; 48:1083-92. [PMID: 16391677 DOI: 10.1139/g05-063] [Citation(s) in RCA: 76] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We performed a detailed karyotype analysis in the codling moth, Cydia pomonella (L.) (Lepidoptera: Tortricidae), the key pest of pome fruit in the temperate regions of the world. The codling moth karyotype consisted of 2n = 56 chromosomes of a holokinetic type. The chromosomes were classified into 5 groups according to their sizes: extra large (3 pairs), large (3 pairs), medium (15 pairs), small (5 pairs), and dot-like (2 pairs). In pachytene nuclei of both sexes, a curious NOR (nucleolar organizer region) bivalent was observed. It carried 2 nucleoli, each associated with one end of the bivalent. FISH with an 18S ribosomal DNA probe confirmed the presence of 2 clusters of rRNA genes at the opposite ends of the bivalent. In accordance with this finding, 2 homologous NOR chromosomes were identified in mitotic metaphase, each showing hybridization signals at both ends. In highly polyploid somatic nuclei, females showed a large heterochromatin body, the so-called sex chromatin or W chromatin. The heterochromatin body was absent in male nuclei, indicating a WZ/ZZ (female/male) sex chromosome system. In keeping with the sex chromatin status, pachytene oocytes showed a sex chromosome bivalent (WZ) that was easily discernible by its heterochromatic W thread. To study molecular differentiation of the sex chromosomes, we employed genomic in situ hybridization (GISH) and comparative genomic hybridization (CGH). GISH detected the W chromosome by strong binding of the Cy3-labelled, female-derived DNA probe. With CGH, both the Cy3-labelled female-derived probe and Fluor-X labelled male-derived probe evenly bound to the W chromosome. This suggested that the W chromosome is predominantly composed of repetitive DNA sequences occurring scattered in other chromosomes but accumulated in the W chromosome. The demonstrated ways of W chromosome identification will facilitate the development of genetic sexing strains desirable for pest control using the sterile insect technique.
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Affiliation(s)
- Iva Fuková
- Institute of Entomology ASCR, Ceské Budejovice, Czech Republic
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35
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Fujii T, Shimada T. Sex determination in the silkworm, Bombyx mori: a female determinant on the W chromosome and the sex-determining gene cascade. Semin Cell Dev Biol 2007; 18:379-88. [PMID: 17446095 DOI: 10.1016/j.semcdb.2007.02.008] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2007] [Accepted: 02/20/2007] [Indexed: 11/22/2022]
Abstract
In insects, the sex is determined completely by genetic mechanisms, which at least in somatic tissues, are cell autonomous. The sex of the silkworm, Bombyx mori, is strongly controlled by the presence of the W chromosome. Genetic studies using translocations and deletions of W suggested that a presumptive feminizing gene (Fem) is located in a limited region of the W chromosome. Recent genomic studies revealed a small number of potential candidates for the Fem gene in this region. In addition, a Bombyx homologue of the Drosophila sex determining gene doublesex has been identified on an autosome and analyzed. Whereas the Drosophila doublesex gene is regulated by activation of splicing in females, the Bombyx doublesex gene (Bmdsx) encodes female- and male-specific mRNAs regulated via male-specific repression of splicing. The vitellogenin gene (Vg) is a target of the BmDSX protein, which directly binds to the Vg promoter. Furthermore, as ectopic expression of the male-type Bmdsx induces male-like transformation of the sexual organs, BmDSX may control sex-specific morphological characteristics in Bombyx. This suggests that although upstream events in Drosophila and Bombyx sex determination differ, similarities between the two species do exist in downstream genetic control of sex determination.
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Affiliation(s)
- Tsuguru Fujii
- Laboratory of Insect Genetics and Bioscience, Department of Agricultural and Environmental Biology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan
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36
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Fuková I, Traut W, Vítková M, Nguyen P, Kubícková S, Marec F. Probing the W chromosome of the codling moth, Cydia pomonella, with sequences from microdissected sex chromatin. Chromosoma 2006; 116:135-45. [PMID: 17103220 DOI: 10.1007/s00412-006-0086-0] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2006] [Revised: 10/02/2006] [Accepted: 10/04/2006] [Indexed: 10/23/2022]
Abstract
The W chromosome of the codling moth, Cydia pomonella, like that of most Lepidoptera species, is heterochromatic and forms a female-specific sex chromatin body in somatic cells. We collected chromatin samples by laser microdissection from euchromatin and W-chromatin bodies. DNA from the samples was amplified by degenerate oligonucleotide-primed polymerase chain reaction (DOP-PCR) and used to prepare painting probes and start an analysis of the W-chromosome sequence composition. With fluorescence in situ hybridization (FISH), the euchromatin probe labelled all chromosomes, whereas the W-chromatin DNA proved to be a highly specific W-chromosome painting probe. For sequence analysis, DOP-PCR-generated DNA fragments were cloned, sequenced, and tested by Southern hybridization. We recovered single-copy and low-copy W-specific sequences, a sequence that was located only in the W and the Z chromosome, multi-copy sequences that were enriched in the W chromosome but occurred also elsewhere, and ubiquitous multi-copy sequences. Three of the multi-copy sequences were recognized as derived from hitherto unknown retrotransposons. The results show that our approach is feasible and that the W-chromosome composition of C. pomonella is not principally different from that of Bombyx mori or from that of Y chromosomes of several species with an XY sex-determining mechanism. The W chromosome has attracted repetitive sequences during evolution but also contains unique sequences.
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Affiliation(s)
- Iva Fuková
- Institute of Entomology, Biology Centre, ASCR, Branisovská 31, 370 05 Ceské Budejovice, Czech Republic
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Fujii T, Tanaka N, Yokoyama T, Ninaki O, Oshiki T, Ohnuma A, Tazima Y, Banno Y, Ajimura M, Mita K, Seki M, Ohbayashi F, Shimada T, Abe H. The female-killing chromosome of the silkworm, Bombyx mori, was generated by translocation between the Z and W chromosomes. Genetica 2006; 127:253-65. [PMID: 16850229 DOI: 10.1007/s10709-005-4147-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2005] [Accepted: 10/17/2005] [Indexed: 10/24/2022]
Abstract
Bombyx mori is a female-heterogametic organism (female, ZW; male, ZZ) that appears to have a putative feminizing gene (Fem) on the W chromosome. The paternally transmitted mutant W chromosome, Df(p ( Sa ) + ( p )W + ( od ))Fem, derived from the translocation-carrying W chromosome (p ( Sa ) + ( p )W + ( od )), is inert as femaleness determinant. Moreover, this Df(p ( Sa ) + ( p )W + ( od ))Fem chromosome has been thought to have a female-killing factor because no female larvae having the Df(p ( Sa ) + ( p )W + ( od ))Fem chromosome are produced. Initially, to investigate whether the Df(p ( Sa ) + ( p )W + ( od ))Fem chromosome contains any region of the W chromosome or not, we analyzed the presence or absence of 12 W-specific RAPD markers. The Df(p ( Sa ) + ( p )W + ( od ))Fem chromosome contained 3 of 12 W-specific RAPD markers. These results strongly indicate that the Df(p ( Sa ) + ( p )W + ( od ))Fem chromosome contains the region of the W chromosome. Moreover, by using phenotypic and molecular markers, we confirmed that the Df(p ( Sa ) + ( p )W + ( od ))Fem chromosome is connected with a partially deleted Z chromosome and that this fused chromosome behaves as a Z chromosome during male meiosis. Furthermore, we demonstrated that the ZZW-type triploid female having the Df(p ( Sa ) + ( p )W + ( od ))Fem chromosome is viable. Therefore, we concluded that the Df(p ( Sa ) + ( p )W + ( od ))Fem chromosome does not have a female-killing factor but that partial deletion of the Z chromosome causes the death of the ZW-type diploid female having the Df(p ( Sa ) + ( p )W + ( od ))Fem chromosome. Additionally, our results of detailed genetic analyses strongly indicate that the female-killing chromosome composed of the Df(p ( Sa ) + ( p )W + ( od ))Fem chromosome and deleted Z chromosome was generated by translocation between the Z chromosome and the translocation-carrying W chromosome, p ( Sa ) + ( p )W + ( od ).
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Affiliation(s)
- T Fujii
- Department of Biological Production, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Saiwai-cho 3-5-8, 183-8509, Fuchu, Tokyo, Japan
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Fujii T, Yokoyama T, Ninagi O, Kakehashi K, Obara Y, Nenoi M, Ishikawa T, Mita K, Shimada T, Abe H. Isolation and characterization of sex chromosome rearrangements generating male muscle dystrophy and female abnormal oogenesis in the silkworm, Bombyx mori. Genetica 2006; 130:267-80. [PMID: 17031495 DOI: 10.1007/s10709-006-9104-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2006] [Accepted: 08/08/2006] [Indexed: 10/24/2022]
Abstract
In deletion-mapping of W-specific RAPD (W-RAPD) markers and putative female determinant gene (Fem), we used X-ray irradiation to break the translocation-carrying W chromosome (W( Ze )). We succeeded in obtaining a fragment of the W( Ze ) chromosome designated as Ze (W), having 3 of 12 W-RAPD markers (W-Bonsai, W-Yukemuri-S, W-Yukemuri-L). Inheritance of the Ze (W) fragment by males indicates that it does not include the Fem gene. On the basis of these results, we determined the relative positions of W-Yukemuri-S and W-Yukemuri-L, and we narrowed down the region where Fem gene is located. In addition to the Ze (W) fragment, the Z chromosome was also broken into a large fragment (Z(1)) having the +( sch ) (1-21.5) and a small fragment (Z(2)) having the +( od ) (1-49.6). Moreover, a new chromosomal fragment (Ze (W)Z(2)) was generated by a fusion event between the Ze (W) and the Z(2) fragments. We analyzed the genetic behavior of the Z(1) fragment and the Ze (W)Z(2) fragment during male (Z/Z(1) Ze (W)Z(2)) and female (Z(1) Ze (W)Z(2)/W) meiosis using phenotypic markers. It was observed that the Z(1) fragment and the Z or the W chromosomes separate without fail. On the other hand, non-disjunction between the Ze (W)Z(2) fragment and the Z chromosome and also between the Ze (W)Z(2) fragment and the W chromosome occurred. Furthermore, the females (2A: Z/Ze (W)Z(2)/W) and males (2A: Z/Z(1)) resulting from non-disjunction between the Ze (W)Z(2) fragment and the W chromosome had phenotypic defects: namely, females exhibited abnormal oogenesis and males were flapless due to abnormal indirect flight muscle structure. These results suggest that Z(2) region of the Z chromosome contains dose-sensitive gene(s), which are involved in oogenesis and indirect flight muscle development.
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Affiliation(s)
- T Fujii
- Department of Biological Production, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Saiwai-cho 3-5-8, Fuchu, Tokyo 183-8509, Japan
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Niimi T, Sahara K, Oshima H, Yasukochi Y, Ikeo K, Traut W. Molecular cloning and chromosomal localization of the Bombyx Sex-lethal gene. Genome 2006; 49:263-8. [PMID: 16604109 DOI: 10.1139/g05-108] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We cloned Bm-Sxl, an orthologue of the Drosophila melanogaster Sex-lethal (Sxl) gene from embryos of Bombyx mori. The full-length cDNAs were of 2 sizes, 1528 and 1339 bp, and were named Bm-Sxl-L and Bm-Sxl-S, respectively. Bm-Sxl-L consists of 8 exons and spans more than 20 kb of genomic DNA. The open reading frame (ORF) codes for a protein 336 amino acids in length. Bm-Sxl-S is a splice variant that lacks the second exon. This creates a new translation start 138 nucleotides downstream and an ORF that codes for 46 amino acids fewer at the N-terminus. Linkage analysis using an F2 panel mapped Bm-Sxl to linkage group 16 at 69.8 cM. We isolated 2 BACs that include the Bm-Sxl gene. With BAC-FISH we located Bm-Sxl cytogenetically on the chromosome corresponding to linkage group 16 (LG16) at position >68.8 cM.
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Affiliation(s)
- Teruyuki Niimi
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
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Yasukochi Y, Ashakumary LA, Baba K, Yoshido A, Sahara K. A second-generation integrated map of the silkworm reveals synteny and conserved gene order between lepidopteran insects. Genetics 2006; 173:1319-28. [PMID: 16547103 PMCID: PMC1526672 DOI: 10.1534/genetics.106.055541] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A second-generation linkage map was constructed for the silkworm, Bombyx mori, focusing on mapping Bombyx sequences appearing in public nucleotide databases and bacterial artificial chromosome (BAC) contigs. A total of 874 BAC contigs containing 5067 clones (22% of the library) were constructed by PCR-based screening with sequence-tagged sites (STSs) derived from whole-genome shotgun (WGS) sequences. A total of 523 BAC contigs, including 342 independent genes registered in public databases and 85 expressed sequence tags (ESTs), were placed onto the linkage map. We found significant synteny and conserved gene order between B. mori and a nymphalid butterfly, Heliconius melpomene, in four linkage groups (LGs), strongly suggesting that using B. mori as a reference for comparative genomics in Lepidotera is highly feasible.
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Affiliation(s)
- Yuji Yasukochi
- Insect Genome Laboratory, National Institute of Agrobiological Sciences, Japan.
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Nagaraja GM, Mahesh G, Satish V, Madhu M, Muthulakshmi M, Nagaraju J. Genetic mapping of Z chromosome and identification of W chromosome-specific markers in the silkworm, Bombyx mori. Heredity (Edinb) 2005; 95:148-57. [PMID: 15931240 DOI: 10.1038/sj.hdy.6800700] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
In the silkworm, Bombyx mori, the female is the heterogametic (ZW) sex and the male is homogametic (ZZ). The female heterogamety is a typical situation in the insect order Lepidoptera. Although the W chromosome in silkworm is strongly female determining, no W-linked gene for a morphological character has been found on it. The Z chromosome carries important traits of economic value as well as genes for various phenotypic traits, but only 2% of molecular information based on its relative size is known. Studies conducted so far indicate that the Z-linked genes are not dosage compensated. In the present study, we constructed a genetic map of randomly amplified polymorphic DNA fragments (RAPD), simple sequence repeats (SSR), and fluorescent intersimple sequence repeat PCR (FISSR) markers for the Z chromosome using a backcross mapping population. A total of 16 Z-linked markers were identified, characterized, and mapped using od, a recessive trait for translucent skin as an anchor marker yielding a total recombination map of 334.5 cM. The linkage distances obtained suggested that the markers were distributed throughout the Z chromosome. Four RAPD and four SSR markers that were linked to W chromosome were also identified. The proposed mapping approach should be useful to identify and map sex-linked traits in the silkworm. The economic and evolutionary significance of Z- and W-linked genes in silkworm, in particular, and lepidopterans, in general, is discussed.
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Affiliation(s)
- G M Nagaraja
- Laboratory of Molecular Genetics, Centre for DNA Fingerprinting and Diagnostics, ECIL Road, Nacharam, Hyderabad 500076, India
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Abe H, Seki M, Ohbayashi F, Tanaka N, Yamashita J, Fujii T, Yokoyama T, Takahashi M, Banno Y, Sahara K, Yoshido A, Ihara J, Yasukochi Y, Mita K, Ajimura M, Suzuki MG, Oshiki T, Shimada T. Partial deletions of the W chromosome due to reciprocal translocation in the silkworm Bombyx mori. INSECT MOLECULAR BIOLOGY 2005; 14:339-52. [PMID: 16033428 DOI: 10.1111/j.1365-2583.2005.00565.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
In the silkworm, Bombyx mori (female, ZW; male, ZZ), femaleness is determined by the presence of a single W chromosome, irrespective of the number of autosomes or Z chromosomes. The W chromosome is devoid of functional genes, except the putative female-determining gene (Fem). However, there are strains in which chromosomal fragments containing autosomal markers have been translocated on to W. In this study, we analysed the W chromosomal regions of the Zebra-W strain (T(W;3)Ze chromosome) and the Black-egg-W strain (T(W;10)+(w-2) chromosome) at the molecular level. Initially, we undertook a project to identify W-specific RAPD markers, in addition to the three already established W-specific RAPD markers (W-Kabuki, W-Samurai and W-Kamikaze). Following the screening of 3648 arbitrary 10-mer primers, we obtained nine W-specific RAPD marker sequences (W-Bonsai, W-Mikan, W-Musashi, W-Rikishi, W-Sakura, W-Sasuke, W-Yukemuri-L, W-Yukemuri-S and BMC1-Kabuki), almost all of which contained the border regions of retrotransposons, namely portions of nested retrotransposons. We confirmed the presence of eleven out of twelve W-specific RAPD markers in the normal W chromosomes of twenty-five silkworm strains maintained in Japan. These results indicate that the W chromosomes of the strains in Japan are almost identical in type. The Zebra-W strain (T(W;3)Ze chromosome) lacked the W-Samurai and W-Mikan RAPD markers and the Black-egg-W strain (T(W;10)+(w-2) chromosome) lacked the W-Mikan RAPD marker. These results strongly indicate that the regions containing the W-Samurai and W-Mikan RAPD markers or the W-Mikan RAPD marker were deleted in the T(W;3)Ze and T(W;10)+(w-2) chromosomes, respectively, due to reciprocal translocation between the W chromosome and the autosome. This deletion apparently does not affect the expression of Fem; therefore, this deleted region of the W chromosome does not contain the putative Fem gene.
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Affiliation(s)
- H Abe
- Department of Biological Production, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Fuchu, Japan.
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Abe H, Mita K, Yasukochi Y, Oshiki T, Shimada T. Retrotransposable elements on the W chromosome of the silkworm, Bombyx mori. Cytogenet Genome Res 2005; 110:144-51. [PMID: 16093666 DOI: 10.1159/000084946] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2003] [Accepted: 01/30/2004] [Indexed: 11/19/2022] Open
Abstract
The sex chromosomes of the silkworm, Bombyxmori, are designated ZW(XY) for females and ZZ(XX) for males. The W chromosome of B. mori does not recombine with the Z chromosome and autosomes and no genes for morphological characters have been mapped to the W chromosome as yet. Furthermore, femaleness is determined by the presence of a single W chromosome, regardless of the number of autosomes or Z chromosomes. To understand these interesting features of the W chromosome, it is necessary to analyze the W chromosome at the molecular biology level. Initially to isolate DNA sequences specific for the W chromosome as randomly amplified polymorphic DNA (RAPD) markers, we compared the genomic DNAs between males and females by PCR with arbitrary 10-mer primers. To the present, we have identified 12 W-specific RAPD markers, and with the exception of one RAPD marker, all of the deduced amino acid sequences of these W-specific RAPD markers show similarity to previously reported amino acid sequences of retrotransposable elements from various organisms. After constructing a genomic DNA lambda phage library of B. mori we obtained two lambda phage clones, one containing the W-Kabuki RAPD sequence and one containing the W-Samurai RAPD sequence and found that these DNA sequences comprised nested structures of many retrotransposable elements. To further analyze the W chromosome, we obtained 14 W-specific bacterial artificial chromosome (BAC) clones from three BAC libraries and subjected these clones to shotgun sequencing. The resulting assembly of sequences did not produce a single contiguous sequence due to the presence of many retrotransposable elements. Therefore, we coupled PCR with shotgun sequencing. Through these analyses, we found that many long terminal repeat (LTR) and non-LTR retrotransposons, retroposons, DNA transposons and their derivatives, have accumulated on the W chromosome as strata. These results strongly indicate that retrotransposable elements are the main structural component of the W chromosome.
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Affiliation(s)
- H Abe
- Department of Biological Production, Faculty of Agriculture, Tokyo University of Agriculture and Technology, Tokyo, Japan.
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Yoshido A, Marec F, Sahara K. Resolution of sex chromosome constitution by genomic in situ hybridization and fluorescence in situ hybridization with (TTAGG) n telomeric probe in some species of Lepidoptera. Chromosoma 2005; 114:193-202. [PMID: 16021495 DOI: 10.1007/s00412-005-0013-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2005] [Revised: 06/15/2005] [Accepted: 06/21/2005] [Indexed: 11/28/2022]
Abstract
We have developed a simple method to resolve the sex chromosome constitution in females of Lepidoptera by using a combination of genomic in situ hybridization (GISH) and fluorescence in situ hybridization with (TTAGG)( n ) telomeric probe (telomere-FISH). In pachytene configurations of sex chromosomes, GISH differentiated W heterochromatin and telomere-FISH detected the chromosome ends. With this method we showed that Antheraea yamamai has a standard system with a fully differentiated W-Z sex chromosome pair. In Orgyia antiqua, we confirmed the presence of neo-W and neo-Z chromosomes, which most probably originated by fusion of the ancestral W and Z with an autosome pair. In contrast to earlier data, Orgyia thyellina females displayed a neo-ZW(1)W(2) sex chromosome constitution. A neo-WZ(1)Z(2) trivalent was found in females of Samia cynthia subsp. indet., originating from a population in Nagano, Japan. Whereas another subspecies collected in Sapporo, Japan, and determined as S. cynthia walkeri, showed a neo-W/neo-Z bivalent similar to O. antiqua, and the subspecies S. cynthia ricini showed a Z univalent (a Z/ZZ system). The combination of GISH and telomere-FISH enabled us to acquire not only reliable information about sex chromosome constitution but also an insight into sex chromosome evolution in Lepidoptera.
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Affiliation(s)
- Atsuo Yoshido
- Division of Applied Bioscience, Graduate School of Agriculture, Hokkaido University N9, W9, Kita-ku, Sapporo 060-8589, Japan
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Yoshido A, Bando H, Yasukochi Y, Sahara K. The Bombyx mori karyotype and the assignment of linkage groups. Genetics 2005; 170:675-85. [PMID: 15802516 PMCID: PMC1450397 DOI: 10.1534/genetics.104.040352] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Lepidopteran species have a relatively high number of small holocentric chromosomes (Bombyx mori, 2n = 56). Chromosome identification has long been hampered in this group by the high number and by the absence of suitable markers like centromere position and chromosome bands. In this study, we carried out fluorescence in situ hybridization (FISH) on meiotic chromosome complements using genetically mapped B. mori bacterial artificial chromosomes (BACs) as probes. The combination of two to four either green or red fluorescence-labeled probes per chromosome allowed us to recognize unequivocally each of the 28 bivalents of the B. mori karyotype by its labeling pattern. Each chromosome was assigned one of the already established genetic linkage groups and the correct orientation in the chromosome was defined. This facilitates physical mapping of any other sequence and bears relevance for the ongoing B. mori genome projects. Two-color BAC-FISH karyotyping overcomes the problem of chromosome recognition in organisms where conventional banding techniques are not available.
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Affiliation(s)
- Atsuo Yoshido
- Division of Applied Bioscience, Graduate School of Agriculture, Hokkaido University, Sapporo, Japan
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Goldsmith MR, Shimada T, Abe H. The genetics and genomics of the silkworm, Bombyx mori. ANNUAL REVIEW OF ENTOMOLOGY 2005; 50:71-100. [PMID: 15355234 DOI: 10.1146/annurev.ento.50.071803.130456] [Citation(s) in RCA: 324] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
We review progress in applying molecular genetic and genomic technologies to studies in the domesticated silkworm, Bombyx mori, highlighting its use as a model for Lepidoptera, and in sericulture and biotechnology. Dense molecular linkage maps are being integrated with classical linkage maps for positional cloning and marker-assisted selection. Classical mutations have been identified by a candidate gene approach. Cytogenetic and sequence analyses show that the W chromosome is composed largely of nested full-length long terminal repeat retrotransposons. Z-chromosome-linked sequences show a lack of dosage compensation. The downstream sex differentiation mechanism has been studied via the silkworm homolog of doublesex. Expressed sequence tagged databases have been used to discover Lepidoptera-specific genes, provide evidence for horizontal gene transfer, and construct microarrays. Physical maps using large-fragment bacterial artificial chromosome libraries have been constructed, and whole-genome shotgun sequencing is underway. Germline transformation and transient expression systems are well established and available for functional studies, high-level protein expression, and gene silencing via RNA interference.
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Affiliation(s)
- Marian R Goldsmith
- Biological Sciences Department, University of Rhode Island, Kingston, Rhode Island 02881, USA.
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Yasukochi Y, Ashakumary LA, Wu C, Yoshido A, Nohata J, Mita K, Sahara K. Organization of the Hox gene cluster of the silkworm, Bombyx mori: a split of the Hox cluster in a non-Drosophila insect. Dev Genes Evol 2004; 214:606-14. [PMID: 15490231 DOI: 10.1007/s00427-004-0441-1] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2003] [Accepted: 08/12/2004] [Indexed: 11/24/2022]
Abstract
A bacterial artificial chromosome (BAC) contig was constructed by chromosome walking, starting from the Hox genes of the silkworm, Bombyx mori. Bombyx orthologues of the labial (lab) and zerknult (zen) genes were newly identified. The size of the BAC contig containing the Hox gene cluster-except the lab and Hox 2 genes-was estimated to be more than 2 Mb. The Bombyx Hox cluster was mapped to linkage group (LG) 6. The lab gene was mapped on the same LG, but far apart from the cluster. Fluorescence in situ hybridization analysis confirmed that the major Hox gene cluster and lab were at different locations on the same chromosome in B. mori.
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Affiliation(s)
- Yuji Yasukochi
- Insect Genome Laboratory, National Institute of Agrobiological Sciences, Tsukuba, 305-8634, Ibaraki, Japan.
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