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Chen L, Huang Y, Pan QH, Wang MY, Liang JJ, Chen TS. Chinese medaka (Oryzias sinensis) dmrt1 gene converts female to male in medaka (Oryzias latipes). Biochim Biophys Acta Gen Subj 2024:130664. [PMID: 38942152 DOI: 10.1016/j.bbagen.2024.130664] [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: 01/13/2024] [Revised: 06/24/2024] [Accepted: 06/25/2024] [Indexed: 06/30/2024]
Abstract
BACKGROUND Chinese medaka (Oryzias sinensis) is widely distributed in freshwater rivers in China. Similar to the medaka (Oryzias latipes), Chinese medaka has the characteristics of small size, rapid reproductive cycle, and strong adaptability, which makes it suitable as a model organism for studies in basic biology and environmental toxicology. Chinese medaka exhibits distinct sexual dimorphism. However, due to the lack of complete genomic information, the regulation of sex determination and differentiation-related genes in Chinese medaka remains unclear. METHODS Chinese medaka dmrt1 (Osdmrt1) was cloned by PCR, and transgenic individuals of medaka [Tg(CMV:Osdmrt1)] overexpressing Osdmrt1 were generated to investigated the role of Osdmrt1 in sex determination. Western blot wasused to validate the integration of the Osdmrt1 into the medaka genome. Tissue sectioning and HE staining were used to identify Tg(CMV:Osdmrt1) physiological gender and phenotype. qRT-PCR was used to analyzed the expression of gonad specific genes. RESULTS Osdmrt1 was cloned and identified, and which shared similar evolutionary relationships with medaka Dmrt1. Tg(CMV:Osdmrt1) exhibited partial sex reversal from female to male in the F2 generation, with genetically female individuals developing testes and producing functional sperm. Additionally, secondary sexual characteristics of the transgenic females also changed to male. CONCLUSION Chinese medaka dmrt1 gene could converts female to male in medaka. GENERAL SIGNIFICANCE These results not only elucidating the function of Chinese medaka dmrt1, but also accumulated knowledge for studying the function of economic fish functional genes in model fish by transgenic technology.
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Affiliation(s)
- Lei Chen
- State Key Laboratory of Mariculture Breeding; Engineering Research Center of the Modern Technology for Eel Industry, Ministry of Education; Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture and Rural Affairs, Fisheries College of Jimei University, Xiamen 361021, China
| | - Yan Huang
- State Key Laboratory of Mariculture Breeding; Engineering Research Center of the Modern Technology for Eel Industry, Ministry of Education; Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture and Rural Affairs, Fisheries College of Jimei University, Xiamen 361021, China
| | - Qi-Hua Pan
- State Key Laboratory of Mariculture Breeding; Engineering Research Center of the Modern Technology for Eel Industry, Ministry of Education; Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture and Rural Affairs, Fisheries College of Jimei University, Xiamen 361021, China
| | - Meng-Yang Wang
- State Key Laboratory of Mariculture Breeding; Engineering Research Center of the Modern Technology for Eel Industry, Ministry of Education; Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture and Rural Affairs, Fisheries College of Jimei University, Xiamen 361021, China
| | - Jing-Jie Liang
- State Key Laboratory of Mariculture Breeding; Engineering Research Center of the Modern Technology for Eel Industry, Ministry of Education; Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture and Rural Affairs, Fisheries College of Jimei University, Xiamen 361021, China
| | - Tian-Sheng Chen
- State Key Laboratory of Mariculture Breeding; Engineering Research Center of the Modern Technology for Eel Industry, Ministry of Education; Key Laboratory of Healthy Mariculture for the East China Sea, Ministry of Agriculture and Rural Affairs, Fisheries College of Jimei University, Xiamen 361021, China.
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Rajawat D, Panigrahi M, Nayak SS, Bhushan B, Mishra BP, Dutt T. Dissecting the genomic regions of selection on the X chromosome in different cattle breeds. 3 Biotech 2024; 14:50. [PMID: 38268984 PMCID: PMC10803714 DOI: 10.1007/s13205-023-03905-4] [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: 02/09/2023] [Accepted: 12/18/2023] [Indexed: 01/26/2024] Open
Abstract
Mammalian X and Y chromosomes independently evolved from various autosomes approximately 300 million years ago (MYA). To fully understand the relationship between genomic composition and phenotypic diversity arising due to the course of evolution, we have scanned regions of selection signatures on the X chromosome in different cattle breeds. In this study, we have prepared the datasets of 184 individuals of different cattle breeds and explored the complete X chromosome by utilizing four within-population and two between-population methods. There were 23, 25, 30, 17, 17, and 12 outlier regions identified in Tajima's D, CLR, iHS, ROH, FST, and XP-EHH. Bioinformatics analysis showed that these regions harbor important candidate genes like AKAP4 for reproduction in Brown Swiss, MBTS2 for production traits in Brown Swiss and Guernsey, CXCR3 and CITED1 for health traits in Jersey and Nelore, and BMX and CD40LG for regulation of X chromosome inactivation in Nelore and Gir. We identified genes shared among multiple methods, such as TRNAC-GCA and IL1RAPL1, which appeared in Tajima's D, ROH, and iHS analyses. The gene TRNAW-CCA was found in ROH, CLR and iHS analyses. The X chromosome exhibits a distinctive interaction between demographic factors and genetic variations, and these findings may provide new insight into the X-linked selection in different cattle breeds.
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Affiliation(s)
- Divya Rajawat
- Division of Animal Genetics, Indian Veterinary Research Institute, Izatnagar, Bareilly, UP 243122 India
| | - Manjit Panigrahi
- Division of Animal Genetics, Indian Veterinary Research Institute, Izatnagar, Bareilly, UP 243122 India
| | - Sonali Sonejita Nayak
- Division of Animal Genetics, Indian Veterinary Research Institute, Izatnagar, Bareilly, UP 243122 India
| | - Bharat Bhushan
- Division of Animal Genetics, Indian Veterinary Research Institute, Izatnagar, Bareilly, UP 243122 India
| | - B. P. Mishra
- ICAR-National Bureau of Animal Genetic Resources, Karnal, Karnal, India
| | - Triveni Dutt
- Livestock Production and Management Section, Indian Veterinary Research Institute, Izatnagar, Bareilly, UP 243122 India
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Luo H, Zhou H, Jiang S, He C, Xu K, Ding J, Liu J, Qin C, Chen K, Zhou W, Wang L, Yang W, Zhu W, Meng H. Gene Expression Profiling Reveals Potential Players of Sex Determination and Asymmetrical Development in Chicken Embryo Gonads. Int J Mol Sci 2023; 24:14597. [PMID: 37834055 PMCID: PMC10572726 DOI: 10.3390/ijms241914597] [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: 07/27/2023] [Revised: 09/14/2023] [Accepted: 09/15/2023] [Indexed: 10/15/2023] Open
Abstract
Despite the notable progress made in recent years, the understanding of the genetic control of gonadal sex differentiation and asymmetrical ovariogenesis in chicken during embryonic development remains incomplete. This study aimed to identify potential key genes and speculate about the mechanisms associated with ovary and testis development via an analysis of the results of PacBio and Illumina transcriptome sequencing of embryonic chicken gonads at the initiation of sexual differentiation (E4.5, E5.5, and E6.5). PacBio sequencing detected 328 and 233 significantly up-regulated transcript isoforms in females and males at E4.5, respectively. Illumina sequencing detected 95, 296 and 445 DEGs at E4.5, E5.5, and E6.5, respectively. Moreover, both sexes showed asymmetrical expression in gonads, and more DEGs were detected on the left side. There were 12 DEGs involved in cell proliferation shared between males and females in the left gonads. GO analysis suggested that coagulation pathways may be involved in the degradation of the right gonad in females and that blood oxygen transport pathways may be involved in preventing the degradation of the right gonad in males. These results provide a comprehensive expression profile of chicken embryo gonads at the initiation of sexual differentiation, which can serve as a theoretical basis for further understanding the mechanism of bird sex determination and its evolutionary process.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | - He Meng
- Shanghai Key Laboratory of Veterinary Biotechnology, Department of Animal Science, School of Agriculture and Biology, Shanghai Jiao Tong University, Shanghai 200240, China; (H.L.); (H.Z.); (S.J.); (C.H.); (K.X.); (J.D.); (J.L.); (C.Q.); (K.C.); (W.Z.); (L.W.); (W.Y.); (W.Z.)
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Sun X, Zhu H, Zhang C, Ilboudo JPHW, Zhao J, Ma C, Yan C, Liswaniso S, Qin N, Xu R. Transcriptomic analysis of ovarian follicles uncovers the crucial genes relevant to follicle selection and preovulatory hierarchy in hens. J Anim Sci 2023; 101:skad241. [PMID: 37453139 PMCID: PMC10414141 DOI: 10.1093/jas/skad241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 07/11/2023] [Indexed: 07/18/2023] Open
Abstract
Follicle selection and preovulatory hierarchy of hen ovaries were important stages of follicle development and crucially determining egg-laying performance. The selected follicles with a higher expression level of follicle-stimulating hormone receptor (FSHR) mRNA that facilitates response to FSH, and rapidly develops into preovulatory follicles with distinctive characteristics of granulosa cells (GCs) proliferation and differentiation. Identification of the key genes involved in these developmental events is helpful for elucidation of the molecular mechanism underlying egg-laying traits in chicken and other domestic fowl. Herein, the comparative transcriptomic analysis of ovarian prehierarchical follicles before selection (BSF), follicles at selection stage (ASF), and hierarchical follicles (HF) were implemented in the Jilin Black chicken (JB) and Lohmann Brown layer (LB) with the divergences in their egg-laying performance by RNA-sequencing. The results showed that nine deferentially expressed genes (DEGs), including STMN4, FABP3, ROBO2, RSPO4, and DMRT1 were revealed between follicles BSF and ASF; and seventeen DEGs, such as SLC6A15, SLITRK3, PRKG2 and TMC3 were mined between ASF and HF. These two group DEGs being co-expressed between BSF and ASF, and between ASF and HF were compared and substantiated in the JB and LB layers, respectively. Furthermore, 10 signaling pathways, such as cAMP signaling, PPAR signaling pathway, AMPK(Adenosine 5'-monophosphate (AMP)-activated protein kinase) pathway, and estrogen signaling pathway were also identified. Moreover, the roles of two representative candidates ROBO2 and PRKG2 genes presented as downregulated mRNA expression pattern in the transcriptomic profiles were further verified in vitro. The results demonstrated that downregulation of ROBO2 or PRKG2 significantly increased the expression levels of FSHR mRNA and protein with the boosted expression of CCND1, STAR, and BCL-2, whereas remarkably inhibited the expression of Caspase-3, consequently, brought about the decrease of GC apoptosis in the ovarian follicles, but increase of GC proliferation and differentiation serving as the hallmarks for follicle selection. It indicated that ROBO2 and PRKG2 may play indispensable roles in follicle selection and preovulatory hierarchy of hen ovaries separately. Our findings provided a comparative transcriptomic evidence for clarifying the molecular mechanism of the follicle development underlying egg-laying traits in chicken.
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Affiliation(s)
- Xue Sun
- Joint International Research Laboratory of Modern Agricultural Technology, Ministry of Education, Jilin Agricultural University, Changchun 130118, China
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Jilin Agricultural University, Changchun 130118, China
| | - Hongyan Zhu
- Joint International Research Laboratory of Modern Agricultural Technology, Ministry of Education, Jilin Agricultural University, Changchun 130118, China
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Jilin Agricultural University, Changchun 130118, China
- Department of Cell Biology and Genetics, College of Basic Medical Science, Jinzhou Medical University, Jinzhou, 121001, Liaoning, China
| | - Changyan Zhang
- Joint International Research Laboratory of Modern Agricultural Technology, Ministry of Education, Jilin Agricultural University, Changchun 130118, China
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Jilin Agricultural University, Changchun 130118, China
| | - Jean Philippe Harold Wensesso Ilboudo
- Joint International Research Laboratory of Modern Agricultural Technology, Ministry of Education, Jilin Agricultural University, Changchun 130118, China
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Jilin Agricultural University, Changchun 130118, China
| | - Jinghua Zhao
- Joint International Research Laboratory of Modern Agricultural Technology, Ministry of Education, Jilin Agricultural University, Changchun 130118, China
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Jilin Agricultural University, Changchun 130118, China
| | - Chang Ma
- Joint International Research Laboratory of Modern Agricultural Technology, Ministry of Education, Jilin Agricultural University, Changchun 130118, China
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Jilin Agricultural University, Changchun 130118, China
| | - Chunchi Yan
- Joint International Research Laboratory of Modern Agricultural Technology, Ministry of Education, Jilin Agricultural University, Changchun 130118, China
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Jilin Agricultural University, Changchun 130118, China
| | - Simushi Liswaniso
- Joint International Research Laboratory of Modern Agricultural Technology, Ministry of Education, Jilin Agricultural University, Changchun 130118, China
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Jilin Agricultural University, Changchun 130118, China
| | - Ning Qin
- Joint International Research Laboratory of Modern Agricultural Technology, Ministry of Education, Jilin Agricultural University, Changchun 130118, China
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Jilin Agricultural University, Changchun 130118, China
| | - Rifu Xu
- Joint International Research Laboratory of Modern Agricultural Technology, Ministry of Education, Jilin Agricultural University, Changchun 130118, China
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, Jilin Agricultural University, Changchun 130118, China
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Gatto KP, Timoshevskaya N, Smith JJ, Lourenço LB. Sequencing of laser captured Z and W chromosomes of the tocantins paradoxical frog (Pseudis tocantins) provides insights on repeatome and chromosomal homology. J Evol Biol 2022; 35:1659-1674. [PMID: 35642451 DOI: 10.1111/jeb.14027] [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: 12/30/2021] [Revised: 04/06/2022] [Accepted: 05/09/2022] [Indexed: 11/30/2022]
Abstract
Pseudis tocantins is the only frog species of the hylid genus Pseudis that possesses highly heteromorphic sex chromosomes. Z and W chromosomes of Ps. tocantins differ in size, morphology, position of the nucleolar organizer region (NOR) and the amount and distribution of heterochromatin. A chromosomal inversion and heterochromatin amplification on the W chromosome were previously inferred to be involved in the evolution of this sex chromosome pair. Despite these findings, knowledge related to the molecular composition of the large heterochromatic band of this W chromosome is restricted to the PcP190 satellite DNA, and no data are available regarding the gene content of either the W or the Z chromosome of Ps. tocantins. Here, we sequenced microdissected Z and W chromosomes of this species to further resolve their molecular composition. Comparative genomic analysis suggests that Ps. tocantins sex chromosomes are likely homologous to chromosomes 4 and 10 of Xenopus tropicalis. Analyses of the repetitive DNA landscape in the Z and W assemblies allowed for the identification of several transposable elements and putative satellite DNA sequences. Finally, some transposable elements from the W assembly were found to be highly diverse and divergent from elements found elsewhere in the genome, suggesting a rapid amplification of these elements on the W chromosome.
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Affiliation(s)
- Kaleb Pretto Gatto
- Laboratory of Chromosome Studies, Department of Structural and Functional Biology, Institute of Biology, University of Campinas, Campinas, Brazil.,Laboratory of Herpetology and Aquaculture Center, Department of Zoology, Institute of Biosciences, São Paulo State University, Rio Claro, Brazil
| | - Nataliya Timoshevskaya
- Department of Biology, College of Arts and Sciences, University of Kentucky, Lexington, Kentucky, USA
| | - Jeramiah J Smith
- Department of Biology, College of Arts and Sciences, University of Kentucky, Lexington, Kentucky, USA
| | - Luciana Bolsoni Lourenço
- Laboratory of Chromosome Studies, Department of Structural and Functional Biology, Institute of Biology, University of Campinas, Campinas, Brazil
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Lv J, Li R, Su Z, Gao B, Ti X, Yan D, Liu G, Liu P, Wang C, Li J. A chromosome-level genome of Portunus trituberculatus provides insights into its evolution, salinity adaptation and sex determination. Mol Ecol Resour 2021; 22:1606-1625. [PMID: 34854556 DOI: 10.1111/1755-0998.13564] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 11/20/2021] [Accepted: 11/24/2021] [Indexed: 01/14/2023]
Abstract
Portunus trituberculatus (Crustacea: Decapoda: Brachyura), commonly known as the swimming crab, is of major ecological importance, as well as being important to the fisheries industry. P. trituberculatus is also an important farmed species in China due to its rapid growth rate and high economic value. Here, we report the genome sequence of the swimming crab, which was assembled at the chromosome scale, covering ~1.2 Gb, with 79.99% of the scaffold sequences assembled into 53 chromosomes. The contig and scaffold N50 values were 108.7 kb and 15.6 Mb, respectively, with 19,981 protein-coding genes. Based on comparative genomic analyses of crabs and shrimps, the C2H2 zinc finger protein family was found to be the only gene family expanded in crab genomes, suggesting it was closely related to the evolution of crabs. The combination of transcriptome and bulked segregant analysis provided insights into the genetic basis of salinity adaptation and rapid growth in P. trituberculatus. In addition, the specific region of the Y chromosome was located for the first time in the genome of P. trituberculatus, and three genes were preliminarily identified as candidate genes for sex determination in this region. Decoding the swimming crab genome not only provides a valuable genomic resource for further biological and evolutionary studies, but is also useful for molecular breeding of swimming crabs.
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Affiliation(s)
- Jianjian Lv
- Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture, China, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, China.,Function Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Aoshanwei Town, Jimo, Qingdao, China
| | - Ronghua Li
- Key Laboratory of Applied Marine Biotechnology, Ministry of Education, Ningbo University, Ningbo, China
| | - Zhencheng Su
- Novogene Bioinformatics Institute, Beijing, China
| | - Baoquan Gao
- Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture, China, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, China.,Function Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Aoshanwei Town, Jimo, Qingdao, China
| | - Xingbin Ti
- Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture, China, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, China
| | - Deping Yan
- Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture, China, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, China
| | | | - Ping Liu
- Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture, China, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, China.,Function Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Aoshanwei Town, Jimo, Qingdao, China
| | - Chunlin Wang
- Key Laboratory of Applied Marine Biotechnology, Ministry of Education, Ningbo University, Ningbo, China
| | - Jian Li
- Key Laboratory of Sustainable Development of Marine Fisheries, Ministry of Agriculture, China, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, China.,Function Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Aoshanwei Town, Jimo, Qingdao, China
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Estermann MA, Major AT, Smith CA. Genetic Regulation of Avian Testis Development. Genes (Basel) 2021; 12:1459. [PMID: 34573441 PMCID: PMC8470383 DOI: 10.3390/genes12091459] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 09/16/2021] [Accepted: 09/16/2021] [Indexed: 11/30/2022] Open
Abstract
As in other vertebrates, avian testes are the site of spermatogenesis and androgen production. The paired testes of birds differentiate during embryogenesis, first marked by the development of pre-Sertoli cells in the gonadal primordium and their condensation into seminiferous cords. Germ cells become enclosed in these cords and enter mitotic arrest, while steroidogenic Leydig cells subsequently differentiate around the cords. This review describes our current understanding of avian testis development at the cell biology and genetic levels. Most of this knowledge has come from studies on the chicken embryo, though other species are increasingly being examined. In chicken, testis development is governed by the Z-chromosome-linked DMRT1 gene, which directly or indirectly activates the male factors, HEMGN, SOX9 and AMH. Recent single cell RNA-seq has defined cell lineage specification during chicken testis development, while comparative studies point to deep conservation of avian testis formation. Lastly, we identify areas of future research on the genetics of avian testis development.
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Affiliation(s)
| | | | - Craig Allen Smith
- Department of Anatomy and Developmental Biology, Monash Biomedicine Discovery Institute, Monash University, Clayton, VIC 3800, Australia; (M.A.E.); (A.T.M.)
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Karyotypic Evolution of Sauropsid Vertebrates Illuminated by Optical and Physical Mapping of the Painted Turtle and Slider Turtle Genomes. Genes (Basel) 2020; 11:genes11080928. [PMID: 32806747 PMCID: PMC7464131 DOI: 10.3390/genes11080928] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 07/25/2020] [Accepted: 07/31/2020] [Indexed: 02/07/2023] Open
Abstract
Recent sequencing and software enhancements have advanced our understanding of the evolution of genomic structure and function, especially addressing novel evolutionary biology questions. Yet fragmentary turtle genome assemblies remain a challenge to fully decipher the genetic architecture of adaptive evolution. Here, we use optical mapping to improve the contiguity of the painted turtle (Chrysemys picta) genome assembly and use de novo fluorescent in situ hybridization (FISH) of bacterial artificial chromosome (BAC) clones, BAC-FISH, to physically map the genomes of the painted and slider turtles (Trachemys scripta elegans). Optical mapping increased C. picta's N50 by ~242% compared to the previous assembly. Physical mapping permitted anchoring ~45% of the genome assembly, spanning 5544 genes (including 20 genes related to the sex determination network of turtles and vertebrates). BAC-FISH data revealed assembly errors in C. picta and T. s. elegans assemblies, highlighting the importance of molecular cytogenetic data to complement bioinformatic approaches. We also compared C. picta's anchored scaffolds to the genomes of other chelonians, chicken, lizards, and snake. Results revealed a mostly one-to-one correspondence between chromosomes of painted and slider turtles, and high homology among large syntenic blocks shared with other turtles and sauropsids. Yet, numerous chromosomal rearrangements were also evident across chelonians, between turtles and squamates, and between avian and non-avian reptiles.
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Transcriptome analysis of genes related to gonad differentiation and development in Muscovy ducks. BMC Genomics 2020; 21:438. [PMID: 32590948 PMCID: PMC7318502 DOI: 10.1186/s12864-020-06852-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2019] [Accepted: 06/19/2020] [Indexed: 01/08/2023] Open
Abstract
BACKGROUND Sex-related genes play a crucial role in gonadal differentiation into testes or ovaries. However, the genetic control of gonadal differentiation in Muscovy ducks remains unknown. Therefore, the objective of our study was to screen new candidate genes associated with ovarian and testicular development. RESULTS In this study, 24 males before gonadal differentiation (MB), 24 females before gonadal differentiation (FB), 24 males after gonadal differentiation (MA) and 24 females after gonadal differentiation (FA) were selected from Putian Muscovy ducks, forming 4 groups. RNA-Seq revealed 101.76 Gb of clean reads and 2800 differentially expressed genes (DEGs), including 46 in MB vs FB, 609 in MA vs FA, 1027 in FA vs FB, and 1118 in MA vs MB. A total of 146 signalling pathways were enriched by KEGG analysis, among which 20, 108, 108 and 116 signalling pathways were obtained in MB vs FB, MA vs MB, MA vs FA and FA vs FB, respectively. In further GO and KEGG analyses, a total of 21 candidate genes related to gonad differentiation and development in Muscovy ducks were screened. Among these, 9 genes were involved in the differentiation and development of the testes, and 12 genes were involved in the differentiation and development of the ovaries. In addition, RNA-Seq data revealed 2744 novel genes. CONCLUSIONS RNA-Seq data revealed 21 genes related to gonadal differentiation and development in Muscovy ducks. We further identified 12 genes, namely, WNT5B, HTRA3, RSPO3, BMP3, HNRNPK, NIPBL, CREB3L4, DKK3, UBE2R2, UBPL3KCMF1, ANXA2, and OSR1, involved in the differentiation and development of ovaries. Moreover, 9 genes, namely, TTN, ATP5A1, DMRT1, DMRT3, AMH, MAP3K1, PIK3R1, AGT and ADAMTSL1, were related to the differentiation and development of testes. Moreover, after gonadal differentiation, DMRT3, AMH, PIK3R1, ADAMTSL1, AGT and TTN were specifically highly expressed in males. WNT5B, ANXA2 and OSR1 were specifically highly expressed in females. These results provide valuable information for studies on the sex control of Muscovy ducks and reveal novel candidate genes for the differentiation and development of testes and ovaries.
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Jeng SR, Wu GC, Yueh WS, Kuo SF, Dufour S, Chang CF. Dmrt1 (doublesex and mab-3-related transcription factor 1) expression during gonadal development and spermatogenesis in the Japanese eel. Gen Comp Endocrinol 2019; 279:154-163. [PMID: 30902612 DOI: 10.1016/j.ygcen.2019.03.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Revised: 03/17/2019] [Accepted: 03/18/2019] [Indexed: 12/23/2022]
Abstract
Dmrt1, doublesex- and mab-3-related transcription factor-1, has been suggested to play critical roles in male gonadogenesis, testicular differentiation and development, including spermatogenesis, among different vertebrates. Vasa is a putative molecular marker of germ cells in vertebrates. In this study, we cloned the full-length dmrt1 cDNA from Japanese eel, and the protein comprised 290 amino acids and presented an extremely conserved Doublesex and Mab-3 (DM) domain. Vasa proteins were expressed in gonadal germ cells in a stage-specific manner, and were expressed at high levels in PGC and spermatogonia, low levels in spermatocytes, and were absent in spermatids and spermatozoa of Japanese eels. Dmrt1 proteins were abundantly expressed in spermatogonia B cells, spermatocytes, spermatids, but not in spermatozoa, spermatogonia A and Sertoli cells. To our knowledge, this study is the first to show a restricted expression pattern for the Dmrt1 protein in spermatogonia B cells, but not spermatogonia A cells, of teleosts. Therefore, Dmrt1 might play vital roles at the specific stages during spermatogenesis from spermatogonia B cells to spermatids in the Japanese eel. Moreover, the Dmrt1 protein exhibited a restricted localization in differentiating oogonia in the early differentiating gonad (ovary-like structure) of male Japanese eels and in E2-induced feminized Japanese eels. We proposed that dmrt1 may be not only required for spermatogenesis but might also play a role in oogenesis in the Japanese eel.
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Affiliation(s)
- Shan-Ru Jeng
- Department of Aquaculture, National Kaohsiung University of Science and Technology, Kaohsiung 811, Taiwan
| | - Guan-Chung Wu
- Department of Aquaculture, National Taiwan Ocean University, Keelung 202, Taiwan; Center of Excellence for the Oceans, National Taiwan Ocean University, Keelung 202, Taiwan.
| | - Wen-Shiun Yueh
- Department of Aquaculture, National Kaohsiung University of Science and Technology, Kaohsiung 811, Taiwan
| | - Shu-Fen Kuo
- Department of Aquaculture, National Kaohsiung University of Science and Technology, Kaohsiung 811, Taiwan
| | - Sylvie Dufour
- Laboratory Biology of Aquatic Organisms and Ecosystems (BOREA), Museum National d'Histoire Naturelle, CNRS, IRD, Sorbonne Université, Université de Caen Normandie, Université des Antilles, 75231 Paris Cedex 05, France
| | - Ching-Fong Chang
- Department of Aquaculture, National Taiwan Ocean University, Keelung 202, Taiwan; Center of Excellence for the Oceans, National Taiwan Ocean University, Keelung 202, Taiwan.
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11
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Yazdi HP, Ellegren H. A Genetic Map of Ostrich Z Chromosome and the Role of Inversions in Avian Sex Chromosome Evolution. Genome Biol Evol 2018; 10:2049-2060. [PMID: 30099482 PMCID: PMC6105114 DOI: 10.1093/gbe/evy163] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/27/2018] [Indexed: 12/11/2022] Open
Abstract
Recombination arrest is a necessary step for the evolution of distinct sex chromosomes. Structural changes, such as inversions, may represent the mechanistic basis for recombination suppression and comparisons of the structural organization of chromosomes as given by chromosome-level assemblies offer the possibility to infer inversions across species at some detail. In birds, deduction of the process of sex chromosome evolution has been hampered by the lack of a validated chromosome-level assembly from a representative of one of the two basal clades of modern birds, Paleognathae. We therefore developed a high-density genetic linkage map of the ostrich Z chromosome and used this to correct an existing assembly, including correction of a large chimeric superscaffold and the order and orientation of other superscaffolds. We identified the pseudoautosomal region as a 52 Mb segment (≈60% of the Z chromosome) where recombination occurred in both sexes. By comparing the order and location of genes on the ostrich Z chromosome with that of six bird species from the other major clade of birds (Neognathae), and of reptilian outgroup species, 25 Z-linked inversions were inferred in the avian lineages. We defined Z chromosome organization in an early avian ancestor and identified inversions spanning the candidate sex-determining DMRT1 gene in this ancestor, which could potentially have triggered the onset of avian sex chromosome evolution. We conclude that avian sex chromosome evolution has been characterized by a complex process of probably both Z-linked and W-linked inversions (and/or other processes). This study illustrates the need for validated chromosome-level assemblies for inference of genome evolution.
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Affiliation(s)
- Homa Papoli Yazdi
- Department of Evolutionary Biology, Evolutionary Biology Centre, Uppsala, Sweden
| | - Hans Ellegren
- Department of Evolutionary Biology, Evolutionary Biology Centre, Uppsala, Sweden
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12
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Li DR, Ye HL, Yang JS, Yang F, Wang MR, De Vos S, Vuylsteke M, Sorgeloos P, Van Stappen G, Bossier P, Yang WJ. Identification and characterization of a Masculinizer (Masc) gene involved in sex differentiation in Artemia. Gene 2017; 614:56-64. [PMID: 28300613 DOI: 10.1016/j.gene.2017.03.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 02/17/2017] [Accepted: 03/10/2017] [Indexed: 11/15/2022]
Abstract
The sex of relatively primitive animals such as invertebrates is mostly determined by environmental factors and chromosome ploidy. Heteromorphic chromosomes may also play an important role, as in the ZW system in lepidopterans. However, the mechanisms of these various sex determination systems are still largely undefined. In the present study, a Masculinizer gene (Ar-Masc) was identified in the crustacean Artemia franciscana Kellogg 1906. Sequence analysis revealed that the 1140-bp full-length open reading frame of Ar-Masc encodes a 380-aa protein containing two CCCH-type zinc finger domains having a high degree of shared identities with the MASC protein characterized in the silkworm Bombyx mori, which has been determined to participate in the production of male-specific splice variants. Furthermore, although Ar-Masc could be detected in almost all stages in both sexual and parthenogenetic Artemia, there were significant variations in expression between these two reproductive modes. Firstly, qRT-PCR and Western blot analysis showed that levels of both Ar-Masc mRNA and protein in sexual nauplii were much higher than in parthenogenetic nauplii throughout the hatching process. Secondly, both sexual and parthenogenetic Artemia had decreased levels of Ar-Masc along with the embryonic developmental stages, while the sexual ones had a relatively higher and more stable expression than those of parthenogenetic ones. Thirdly, immunofluorescence analysis determined that sexual individuals had higher levels of Ar-MASC protein than parthenogenetic individuals during embryonic development. Lastly, RNA interference with dsRNA showed that gene silencing of Ar-Masc in sexual A. franciscana caused the female-male ratio of progeny to be 2.19:1. These data suggest that Ar-Masc participates in the process of sex determination in A. franciscana, and provide insight into the evolution of sex determination in sexual organisms.
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Affiliation(s)
- Dong-Rui Li
- College of Life Sciences, Zhejiang University, Hangzhou 310058, People's Republic of China
| | - Hui-Li Ye
- College of Life Sciences, Zhejiang University, Hangzhou 310058, People's Republic of China
| | - Jin-Shu Yang
- College of Life Sciences, Zhejiang University, Hangzhou 310058, People's Republic of China
| | - Fan Yang
- College of Life Sciences, Zhejiang University, Hangzhou 310058, People's Republic of China
| | - Mo-Ran Wang
- Tianjin Key Laboratory of Aqua-Ecology and Aquaculture, Department of Fisheries Science, Tianjin Agricultural University, People's Republic of China
| | - Stephanie De Vos
- Laboratory of Aquaculture &Artemia Reference center, Ghent University, Belgium
| | - Marnik Vuylsteke
- Laboratory of Aquaculture &Artemia Reference center, Ghent University, Belgium
| | - Patrick Sorgeloos
- Laboratory of Aquaculture &Artemia Reference center, Ghent University, Belgium
| | - Gilbert Van Stappen
- Laboratory of Aquaculture &Artemia Reference center, Ghent University, Belgium
| | - Peter Bossier
- Laboratory of Aquaculture &Artemia Reference center, Ghent University, Belgium
| | - Wei-Jun Yang
- College of Life Sciences, Zhejiang University, Hangzhou 310058, People's Republic of China.
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13
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Yano CF, Bertollo LAC, Ezaz T, Trifonov V, Sember A, Liehr T, Cioffi MB. Highly conserved Z and molecularly diverged W chromosomes in the fish genus Triportheus (Characiformes, Triportheidae). Heredity (Edinb) 2016; 118:276-283. [PMID: 28000659 DOI: 10.1038/hdy.2016.83] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Revised: 06/24/2016] [Accepted: 07/08/2016] [Indexed: 11/09/2022] Open
Abstract
The main objectives of this study were to test: (1) whether the W-chromosome differentiation matches to species' evolutionary divergence (phylogenetic concordance) and (2) whether sex chromosomes share a common ancestor within a congeneric group. The monophyletic genus Triportheus (Characiformes, Triportheidae) was the model group for this study. All species in this genus so far analyzed have ZW sex chromosome system, where the Z is always the largest chromosome of the karyotype, whereas the W chromosome is highly variable ranging from almost homomorphic to highly heteromorphic. We applied conventional and molecular cytogenetic approaches including C-banding, ribosomal DNA mapping, comparative genomic hybridization (CGH) and cross-species whole chromosome painting (WCP) to test our questions. We developed Z- and W-chromosome paints from T. auritus for cross-species WCP and performed CGH in a representative species (T. signatus) to decipher level of homologies and rates of differentiation of W chromosomes. Our study revealed that the ZW sex chromosome system had a common origin, showing highly conserved Z chromosomes and remarkably divergent W chromosomes. Notably, the W chromosomes have evolved to different shapes and sequence contents within ~15-25 Myr of divergence time. Such differentiation highlights a dynamic process of W-chromosome evolution within congeneric species of Triportheus.
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Affiliation(s)
- C F Yano
- Departamento de Genética e Evolução, Universidade Federal de São Carlos, São Carlos, Brazil
| | - L A C Bertollo
- Departamento de Genética e Evolução, Universidade Federal de São Carlos, São Carlos, Brazil
| | - T Ezaz
- Institute for Applied Ecology, University of Canberra, Canberra, Australian Capital Territory, Australia
| | - V Trifonov
- Institute of Molecular and Cellular Biology SB RAS, Novosibirsk, Russia
| | - A Sember
- Laboratory of Fish Genetics, Institute of Animal Physiology and Genetics, Czech Academy of Sciences, Liběchov, Czech Republic
| | - T Liehr
- Jena University Hospital, Friedrich Schiller University, Institute of Human Genetics, Jena, Germany
| | - M B Cioffi
- Departamento de Genética e Evolução, Universidade Federal de São Carlos, São Carlos, Brazil
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14
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Yang X, Deng J, Zheng J, Xia L, Yang Z, Qu L, Chen S, Xu G, Jiang H, Clinton M, Yang N. A Window of MHM Demethylation Correlates with Key Events in Gonadal Differentiation in the Chicken. Sex Dev 2016; 10:152-8. [DOI: 10.1159/000447659] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Indexed: 11/19/2022] Open
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15
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Sreenivasulu K, Ganesh S, Raman R. Evolutionarily conserved, DMRT1, encodes alternatively spliced transcripts and shows dimorphic expression during gonadal differentiation in the lizard, Calotes versicolor. Mech Dev 2016; 119 Suppl 1:S55-64. [PMID: 14516661 DOI: 10.1016/s0925-4773(03)00092-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
An orthologue of Dmrt1 has been cloned and characterized in the lizard, Calotes versicolor (CvDmrt1). CvDmrt1 encodes alternatively spliced transcripts in genital ridge during gonadal differentiation and in adult testis. Its expression in genital ridge initiates from day 3 and is restricted to mesenchymal cells, which differentiate into the Sertoli cells. Lack of expression in the coelomic epithelium of GR shows that CvDmrt1 expression occurs only in the testicular pathway, and that the Sertoli and granulosa cells in GR may originate from different primordia. From day 25 onwards, the expression shifts majorly towards the germ cells both in testis and ovary. Thus its role in sexual differentiation of C. versicolor, which lacks CSD and TSD, is well documented.
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Affiliation(s)
- K Sreenivasulu
- Cytogenetics Laboratory, Department of Zoology, Banaras Hindu University, Varanasi, 221005, India
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16
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Su L, Zhou F, Ding Z, Gao Z, Wen J, Wei W, Wang Q, Wang W, Liu H. Transcriptional variants of Dmrt1 and expression of four Dmrt genes in the blunt snout bream, Megalobrama amblycephala. Gene 2015; 573:205-15. [DOI: 10.1016/j.gene.2015.07.044] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Revised: 06/20/2015] [Accepted: 07/13/2015] [Indexed: 10/23/2022]
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17
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Kaneko H, Ijiri S, Kobayashi T, Izumi H, Kuramochi Y, Wang DS, Mizuno S, Nagahama Y. Gonadal soma-derived factor (gsdf), a TGF-beta superfamily gene, induces testis differentiation in the teleost fish Oreochromis niloticus. Mol Cell Endocrinol 2015; 415:87-99. [PMID: 26265450 DOI: 10.1016/j.mce.2015.08.008] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Revised: 08/05/2015] [Accepted: 08/06/2015] [Indexed: 11/21/2022]
Abstract
The Nile tilapia, Oreochromis niloticus, is a gonochoristic teleost fish with an XX/XY genetic system and is an excellent model for gonadal sex differentiation. In the present study, we screened novel genes that were expressed predominantly in either XY or XX undifferentiated gonads during the critical period for differentiation of gonads into ovaries or testes using microarray screening. We focused on one of the isolated 12 candidate genes, #9475, which was an ortholog of gsdf (gonadal soma-derived factor), a member of the transforming growth factor-beta superfamily. #9475/gsdf showed sexual dimorphism in expression in XY gonads before any other testis differentiation-related genes identified in this species thus far. We also overexpressed the #9475/gsdf gene in XX tilapia, and XX tilapia bearing the #9475/gsdf gene showed normal testis development, which suggests that #9475/gsdf plays an important role in male determination and/or differentiation in tilapia.
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Affiliation(s)
- Hiroyo Kaneko
- Laboratory of Reproductive Biology, National Institute for Basic Biology, Okazaki 444-8585, Japan; SORST, Japan Science Technology Corporation, Kawaguchi, Saitama 332-0012, Japan.
| | - Shigeho Ijiri
- Laboratory of Reproductive Biology, National Institute for Basic Biology, Okazaki 444-8585, Japan; SORST, Japan Science Technology Corporation, Kawaguchi, Saitama 332-0012, Japan; Division of Marine Life Science, Graduate School of Fisheries Sciences, Hokkaido University, Hakodate, Hokkaido 041-8611, Japan.
| | - Tohru Kobayashi
- Laboratory of Reproductive Biology, National Institute for Basic Biology, Okazaki 444-8585, Japan; Laboratory of Molecular Reproductive Biology, Institute for Environmental Sciences, University of Shizuoka, Shizuoka 422-8526, Japan.
| | - Hikari Izumi
- Division of Marine Life Science, Graduate School of Fisheries Sciences, Hokkaido University, Hakodate, Hokkaido 041-8611, Japan.
| | - Yuki Kuramochi
- Division of Marine Life Science, Graduate School of Fisheries Sciences, Hokkaido University, Hakodate, Hokkaido 041-8611, Japan.
| | - De-Shou Wang
- Laboratory of Reproductive Biology, National Institute for Basic Biology, Okazaki 444-8585, Japan; SORST, Japan Science Technology Corporation, Kawaguchi, Saitama 332-0012, Japan.
| | - Shouta Mizuno
- Division of Marine Life Science, Graduate School of Fisheries Sciences, Hokkaido University, Hakodate, Hokkaido 041-8611, Japan.
| | - Yoshitaka Nagahama
- Laboratory of Reproductive Biology, National Institute for Basic Biology, Okazaki 444-8585, Japan; SORST, Japan Science Technology Corporation, Kawaguchi, Saitama 332-0012, Japan; South Ehime Fisheries Research Center, Ehime University, Matsuyama, Ehime 790-8577, Japan.
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18
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Schneider WJ. Lipid transport to avian oocytes and to the developing embryo. J Biomed Res 2015; 30:174-80. [PMID: 26585559 PMCID: PMC4885163 DOI: 10.7555/jbr.30.20150048] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Revised: 05/12/2015] [Accepted: 07/03/2015] [Indexed: 11/25/2022] Open
Abstract
Studies of receptor-mediated lipoprotein metabolic pathways in avian species have revealed that physiological intricacies of specific cell types are highly analogous to those in mammals. A prime example for the power of comparative studies across different animal kingdoms, elucidated in the chicken, is that the expression of different lipoprotein receptors in somatic cells and oocytes are the key to oocyte growth. In avian species, yolk precursor transport from the hen's liver to rapidly growing oocytes and the subsequent transfer of yolk nutrients via the yolk sac to the developing embryo are highly efficient processes. Oocytes grow from a diameter of 5 mm to 2.5-3 cm in only 7 days, and the yolk sac transfers nutrients from the yolk stored in the mature oocyte to the embryo within just 2 weeks. The underlying key transport mechanism is receptor-mediated endocytosis of macromolecules, i.e., of hepatically synthesized yolk precursors for oocyte growth, and of mature yolk components for embryo nutrition, respectively. Recently, the receptors involved, as well as the role of lipoprotein synthesis in the yolk sac have been identified. As outlined here, lipoprotein degradation/resynthesis cycles and the expression of lipoprotein receptors are not only coordinated with the establishment of the follicular architecture embedding the oocyte, but also with the generation of the yolk sac vasculature essential for nutrient transfer to the embryo.
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Affiliation(s)
- Wolfgang J Schneider
- Department of Medical Biochemistry, Max F. Perutz Laboratories, Medical University and Biocenter Vienna, Austria.
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19
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Badenhorst D, Hillier LW, Literman R, Montiel EE, Radhakrishnan S, Shen Y, Minx P, Janes DE, Warren WC, Edwards SV, Valenzuela N. Physical Mapping and Refinement of the Painted Turtle Genome (Chrysemys picta) Inform Amniote Genome Evolution and Challenge Turtle-Bird Chromosomal Conservation. Genome Biol Evol 2015; 7:2038-50. [PMID: 26108489 PMCID: PMC4524486 DOI: 10.1093/gbe/evv119] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/19/2015] [Indexed: 01/04/2023] Open
Abstract
Comparative genomics continues illuminating amniote genome evolution, but for many lineages our understanding remains incomplete. Here, we refine the assembly (CPI 3.0.3 NCBI AHGY00000000.2) and develop a cytogenetic map of the painted turtle (Chrysemys picta-CPI) genome, the first in turtles and in vertebrates with temperature-dependent sex determination. A comparison of turtle genomes with those of chicken, selected nonavian reptiles, and human revealed shared and novel genomic features, such as numerous chromosomal rearrangements. The largest conserved syntenic blocks between birds and turtles exist in four macrochromosomes, whereas rearrangements were evident in these and other chromosomes, disproving that turtles and birds retain fully conserved macrochromosomes for greater than 300 Myr. C-banding revealed large heterochromatic blocks in the centromeric region of only few chromosomes. The nucleolar-organizing region (NOR) mapped to a single CPI microchromosome, whereas in some turtles and lizards the NOR maps to nonhomologous sex-chromosomes, thus revealing independent translocations of the NOR in various reptilian lineages. There was no evidence for recent chromosomal fusions as interstitial telomeric-DNA was absent. Some repeat elements (CR1-like, Gypsy) were enriched in the centromeres of five chromosomes, whereas others were widespread in the CPI genome. Bacterial artificial chromosome (BAC) clones were hybridized to 18 of the 25 CPI chromosomes and anchored to a G-banded ideogram. Several CPI sex-determining genes mapped to five chromosomes, and homology was detected between yet other CPI autosomes and the globally nonhomologous sex chromosomes of chicken, other turtles, and squamates, underscoring the independent evolution of vertebrate sex-determining mechanisms.
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Affiliation(s)
- Daleen Badenhorst
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University
| | | | - Robert Literman
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University
| | | | | | - Yingjia Shen
- The Genome Institute at Washington University, St Louis
| | - Patrick Minx
- The Genome Institute at Washington University, St Louis
| | - Daniel E Janes
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University Department of Organismic and Evolutionary Biology, Harvard University
| | | | - Scott V Edwards
- Department of Organismic and Evolutionary Biology, Harvard University
| | - Nicole Valenzuela
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University
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Tamschick S, Rozenblut-Kościsty B, Bonato L, Dufresnes C, Lymberakis P, Kloas W, Ogielska M, Stöck M. Sex Chromosome Conservation, DMRT1 Phylogeny and Gonad Morphology in Diploid Palearctic Green Toads ( Bufo viridis Subgroup). Cytogenet Genome Res 2015; 144:315-24. [DOI: 10.1159/000380841] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/26/2015] [Indexed: 11/19/2022] Open
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21
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Lima-Filho PA, Amorim KDJ, Cioffi MB, Bertollo LAC, Molina WF. Chromosomal mapping of repetitive DNAs in Gobionellus oceanicus and G. stomatus (Gobiidae; Perciformes): A shared XX/XY system and an unusual distribution of 5S rDNA sites on the Y chromosome. Cytogenet Genome Res 2015; 144:333-40. [PMID: 25720317 DOI: 10.1159/000373909] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/15/2014] [Indexed: 11/19/2022] Open
Abstract
With nearly 2,000 species, Gobiidae is the most specious family of the vertebrates. This high level of speciation is accompanied by conspicuous karyotypic modifications, where the role of repetitive sequences remains largely unknown. This study analyzed the karyotype of 2 species of the genus Gobionellus and mapped 18S and 5S ribosomal RNA genes and (CA)15 microsatellite sequences onto their chromosomes. G. oceanicus (2n = 56; ♂ 12 metacentrics (m) + 4 submetacentrics (sm) + 1 subtelocentric (st) + 39 acrocentrics (a); ♀ 12m + 4sm + 2st + 38a) and G. stomatus (2n = 56; ♂ 20m + 14sm + 1st + 21a; ♀ 20m + 14sm + 2st + 20a) possess the highest diploid chromosome number among the Gobiidae and have different karyotypes. Both species share an XX/XY sex chromosome system with a large subtelocentric X and a small acrocentric Y chromosome which is rich in (CA)15 sequences and bears 5S rRNA sites. Although coding and noncoding repetitive DNA sequences may be involved in the genesis or differentiation of the sex chromosomes, the exclusive presence of 5S rDNA sites on the Y, but not on the X chromosome of both species, represents a novelty in fishes. In summary, the karyotypic differences, as well as new data on the sex chromosome systems in these 2 Gobiidae species, confirm the high chromosomal dynamism observed in this family.
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Affiliation(s)
- Paulo A Lima-Filho
- Department of Cellular Biology and Genetics, Biosciences Center, Federal University of Rio Grande do Norte, Natal, Brazil
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22
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A syntenic region conserved from fish to Mammalian x chromosome. INTERNATIONAL JOURNAL OF EVOLUTIONARY BIOLOGY 2014; 2014:873935. [PMID: 25506037 PMCID: PMC4254068 DOI: 10.1155/2014/873935] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Revised: 10/30/2014] [Accepted: 11/02/2014] [Indexed: 11/29/2022]
Abstract
Sex chromosomes bearing the sex-determining gene initiate development along the male or female pathway, no matter which sex is determined by XY male or ZW female heterogamety. Sex chromosomes originate from ancient autosomes but evolved rapidly after the acquisition of sex-determining factors which are highly divergent between species. In the heterogametic male system (XY system), the X chromosome is relatively evolutionary silent and maintains most of its ancestral genes, in contrast to its Y counterpart that has evolved rapidly and degenerated. Sex in a teleost fish, the Nile tilapia (Oreochromis niloticus), is determined genetically via an XY system, in which an unpaired region is present in the largest chromosome pair. We defined the differences in DNA contents present in this chromosome with a two-color comparative genomic hybridization (CGH) and the random amplified polymorphic DNA (RAPD) approach in XY males. We further identified a syntenic segment within this region that is well conserved in several teleosts. Through comparative genome analysis, this syntenic segment was also shown to be present in mammalian X chromosomes, suggesting a common ancestral origin of vertebrate sex chromosomes.
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Carabajal Paladino LZ, Nguyen P, Síchová J, Marec F. Mapping of single-copy genes by TSA-FISH in the codling moth, Cydia pomonella. BMC Genet 2014; 15 Suppl 2:S15. [PMID: 25471491 PMCID: PMC4255786 DOI: 10.1186/1471-2156-15-s2-s15] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
Background We work on the development of transgenic sexing strains in the codling moth, Cydia pomonella (Tortricidae), which would enable to produce male-only progeny for the population control of this pest using sterile insect technique (SIT). To facilitate this research, we have developed a number of cytogenetic and molecular tools, including a physical map of the codling moth Z chromosome using BAC-FISH (fluorescence in situ hybridization with bacterial artificial chromosome probes). However, chromosomal localization of unique, single-copy sequences such as a transgene cassette by conventional FISH remains challenging. In this study, we adapted a FISH protocol with tyramide signal amplification (TSA-FISH) for detection of single-copy genes in Lepidoptera. We tested the protocol with probes prepared from partial sequences of Z-linked genes in the codling moth. Results Using a modified TSA-FISH protocol we successfully mapped a partial sequence of the Acetylcholinesterase 1 (Ace-1) gene to the Z chromosome and confirmed thus its Z-linkage. A subsequent combination of BAC-FISH with BAC probes containing anticipated neighbouring Z-linked genes and TSA-FISH with the Ace-1 probe allowed the integration of Ace-1 in the physical map of the codling moth Z chromosome. We also developed a two-colour TSA-FISH protocol which enabled us simultaneous localization of two Z-linked genes, Ace-1 and Notch, to the expected regions of the Z chromosome. Conclusions We showed that TSA-FISH represents a reliable technique for physical mapping of genes on chromosomes of moths and butterflies. Our results suggest that this technique can be combined with BAC-FISH and in the future used for physical localization of transgene cassettes on chromosomes of transgenic lines in the codling moth or other lepidopteran species. Furthermore, the developed protocol for two-colour TSA-FISH might become a powerful tool for synteny mapping in non-model organisms.
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Kawagoshi T, Uno Y, Nishida C, Matsuda Y. The Staurotypus turtles and aves share the same origin of sex chromosomes but evolved different types of heterogametic sex determination. PLoS One 2014; 9:e105315. [PMID: 25121779 PMCID: PMC4133349 DOI: 10.1371/journal.pone.0105315] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2014] [Accepted: 07/18/2014] [Indexed: 12/24/2022] Open
Abstract
Reptiles have a wide diversity of sex-determining mechanisms and types of sex chromosomes. Turtles exhibit temperature-dependent sex determination and genotypic sex determination, with male heterogametic (XX/XY) and female heterogametic (ZZ/ZW) sex chromosomes. Identification of sex chromosomes in many turtle species and their comparative genomic analysis are of great significance to understand the evolutionary processes of sex determination and sex chromosome differentiation in Testudines. The Mexican giant musk turtle (Staurotypus triporcatus, Kinosternidae, Testudines) and the giant musk turtle (Staurotypus salvinii) have heteromorphic XY sex chromosomes with a low degree of morphological differentiation; however, their origin and linkage group are still unknown. Cross-species chromosome painting with chromosome-specific DNA from Chinese soft-shelled turtle (Pelodiscus sinensis) revealed that the X and Y chromosomes of S. triporcatus have homology with P. sinensis chromosome 6, which corresponds to the chicken Z chromosome. We cloned cDNA fragments of S. triporcatus homologs of 16 chicken Z-linked genes and mapped them to S. triporcatus and S. salvinii chromosomes using fluorescence in situ hybridization. Sixteen genes were localized to the X and Y long arms in the same order in both species. The orders were also almost the same as those of the ostrich (Struthio camelus) Z chromosome, which retains the primitive state of the avian ancestral Z chromosome. These results strongly suggest that the X and Y chromosomes of Staurotypus turtles are at a very early stage of sex chromosome differentiation, and that these chromosomes and the avian ZW chromosomes share the same origin. Nonetheless, the turtles and birds acquired different systems of heterogametic sex determination during their evolution.
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Affiliation(s)
- Taiki Kawagoshi
- Laboratory of Animal Genetics, Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | - Yoshinobu Uno
- Laboratory of Animal Genetics, Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | - Chizuko Nishida
- Department of Natural History Sciences, Faculty of Science, Hokkaido University, Sapporo, Japan
| | - Yoichi Matsuda
- Laboratory of Animal Genetics, Department of Applied Molecular Biosciences, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
- Avian Bioscience Research Center, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
- * E-mail:
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Ishijima J, Uno Y, Nishida C, Matsuda Y. Genomic structures of the kW1 loci on the Z and W chromosomes in ratite birds: structural changes at an early stage of W chromosome differentiation. Cytogenet Genome Res 2014; 142:255-67. [PMID: 24820528 DOI: 10.1159/000362479] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/24/2014] [Indexed: 11/19/2022] Open
Abstract
The W chromosome of ratite birds shows minimal morphological differentiation and retains homology of genetic linkage and gene order with a substantial stretch of the Z chromosome; however, the molecular structure in the differentiated region is still not well known. The kW1 sequence was isolated from the kiwi as a W-specific DNA marker for PCR-based molecular sexing of ratite birds. In ratite W chromosomes, this sequence commonly contains a ∼200-bp deletion. To characterize the very early event of avian sex chromosome differentiation, we performed molecular cytogenetic analyses of kW1 and its flanking sequences in paleognathous and neognathous birds and reptiles. Female-specific repeats were found in the kW1-flanking sequence of the cassowary (Casuarius casuarius), and the repeats have been amplified in the pericentromeric region of the W chromosomes of ratites, which may have resulted from the cessation of meiotic recombination between the Z and W chromosomes at an early stage of sex chromosome differentiation. The presence of the kW1 sequence in neognathous birds and a crocodilian species suggests that the kW1 sequence was present in the ancestral genome of Archosauria; however, it disappeared in other reptilian taxa and several lineages of neognathous birds.
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Affiliation(s)
- Junko Ishijima
- Laboratory of Animal Cytogenetics, Department of Biological Sciences, Graduate School of Science, Hokkaido University, Sapporo, Japan
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Elkin R, Bauer R, Schneider W. The restricted ovulator chicken strain: an oviparous vertebrate model of reproductive dysfunction caused by a gene defect affecting an oocyte-specific receptor. Anim Reprod Sci 2012; 136:1-13. [PMID: 23123285 PMCID: PMC3521959 DOI: 10.1016/j.anireprosci.2012.10.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2012] [Revised: 09/23/2012] [Accepted: 10/12/2012] [Indexed: 01/26/2023]
Abstract
A unique non-laying strain of chickens with heritable hyperlipidemia and aortic atherosclerosis was first described in 1974. Subsequent work established that the phenotype results from a naturally occurring point mutation in the gene specifying the very low density lipoprotein (VLDL) receptor, a 95-kDa membrane protein which normally mediates the massive uptake of the main circulating hepatically-synthesized yolk precursors, VLDL and vitellogenin. As a result, hens of the mutant strain termed "restricted ovulator" (R/O) have approximately 5-fold elevations in circulating cholesterol and triglyceride concentrations compared with normal layers, and hepatic lipogenesis and cholesterogenesis are markedly attenuated due to feedback inhibition. R/O hens also exhibit hyperestrogenemia, hypoprogesteronemia, elevated circulating gonadotropins, and up-regulated pituitary progesterone receptor mRNA and isoforms. The ovaries of R/O hens are abnormal in that they lack a follicular hierarchy and contain many small preovulatory follicles of various colors, shapes, and sizes. However, since R/O hens occasionally lay eggs, it is possible that endocytic receptors other than the VLDL receptor may be able to facilitate oocyte growth and/or that yolk precursor uptake can occur via a nonspecific bulk process. A mammalian model of impaired fecundity with abnormal lipoprotein metabolism also has been described, but different mechanisms are likely responsible for its reproductive dysfunction. Nevertheless, as our understanding of the molecular physiology and biochemistry of avian oocyte growth continues to expand, in part due to studies of the R/O model, new analogies may emerge between avian and mammalian systems, which ultimately could help to answer important questions in reproductive biology.
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Affiliation(s)
- R.G. Elkin
- Department of Animal Science, The Pennsylvania State University, University Park, PA 16802, USA
| | - R. Bauer
- Department of Medical Biochemistry, Medical University of Vienna, Max F. Perutz Laboratories, Dr. Bohr-Gasse 9/2, A-1030 Vienna, Austria
| | - W.J. Schneider
- Department of Medical Biochemistry, Medical University of Vienna, Max F. Perutz Laboratories, Dr. Bohr-Gasse 9/2, A-1030 Vienna, Austria
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Abstract
Y-linked Dmy (also called dmrt1bY) in the teleost fish medaka, W-linked Dm-W in the African clawed frog (Xenopus laevis), and Z-linked Dmrt1 in the chicken are all sex chromosome-linked Dmrt1 homologues required for sex determination. Dmy and Dm-W both are Dmrt1 palalogues evolved through Dmrt1 duplication, while chicken Dmrt1 is a Z-linked orthologue. The eutherian sex-determining gene, Sry, evolved from an allelic gene, Sox3. Here we analyzed the exon–intron structures of the Dmrt1 homologues of several vertebrate species through information from databases and by determining the transcription initiation sites in medaka, chicken, Xenopus, and mouse. Interestingly, medaka Dmrt1 and Dmy and Xenopus Dm-W and Dmrt1 have a noncoding-type first exon, while mouse and chicken Dmrt1 do not. We next compared the 5′-flanking sequences of the Dmrt1 noncoding and coding exons 1 of several vertebrate species and found conservation of the presumptive binding sites for some transcription factors. Importantly, based on the phylogenetic trees for Dmrt1 and Sox3 homologues, it was implied that the sex-determining gene Dmy, Dm-W, and Sry have a higher substitution rate than thier prototype genes. Finally, we discuss the evolutionary relationships between vertebrate sex chromosomes and the sex-determining genes Dmy/Dm-W and Sry, which evolved by neofunctionalization of Dmrt1 and Sox3, respectively, for sex determining function. We propose a coevolution model of sex determining gene and sex chromosome, in which undifferentiated sex chromosomes easily allow replacement of a sex-determining gene with another new one, while specialized sex chromosomes are restricted a particular sex-determining gene.
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Yamashiro S, Gokhin DS, Kimura S, Nowak RB, Fowler VM. Tropomodulins: pointed-end capping proteins that regulate actin filament architecture in diverse cell types. Cytoskeleton (Hoboken) 2012; 69:337-70. [PMID: 22488942 DOI: 10.1002/cm.21031] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2011] [Revised: 03/23/2012] [Accepted: 03/26/2012] [Indexed: 01/31/2023]
Abstract
Tropomodulins are a family of four proteins (Tmods 1-4) that cap the pointed ends of actin filaments in actin cytoskeletal structures in a developmentally regulated and tissue-specific manner. Unique among capping proteins, Tmods also bind tropomyosins (TMs), which greatly enhance the actin filament pointed-end capping activity of Tmods. Tmods are defined by a TM-regulated/Pointed-End Actin Capping (TM-Cap) domain in their unstructured N-terminal portion, followed by a compact, folded Leucine-Rich Repeat/Pointed-End Actin Capping (LRR-Cap) domain. By inhibiting actin monomer association and dissociation from pointed ends, Tmods regulate actin dynamics and turnover, stabilizing actin filament lengths and cytoskeletal architecture. In this review, we summarize the genes, structural features, molecular and biochemical properties, actin regulatory mechanisms, expression patterns, and cell and tissue functions of Tmods. By understanding Tmods' functions in the context of their molecular structure, actin regulation, binding partners, and related variants (leiomodins 1-3), we can draw broad conclusions that can explain the diverse morphological and functional phenotypes that arise from Tmod perturbation experiments in vitro and in vivo. Tmod-based stabilization and organization of intracellular actin filament networks provide key insights into how the emergent properties of the actin cytoskeleton drive tissue morphogenesis and physiology.
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Affiliation(s)
- Sawako Yamashiro
- Department of Cell Biology, The Scripps Research Institute, La Jolla, California 92037, USA
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Sarre SD, Ezaz T, Georges A. Transitions between sex-determining systems in reptiles and amphibians. Annu Rev Genomics Hum Genet 2011; 12:391-406. [PMID: 21801024 DOI: 10.1146/annurev-genom-082410-101518] [Citation(s) in RCA: 106] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Important technological advances in genomics are driving a new understanding of the evolution of sex determination in vertebrates. In particular, comparative chromosome mapping in reptiles has shown an intriguing distribution of homology in sex chromosomes across reptile groups. When this new understanding is combined with the widespread distribution of genetic and temperature-dependent sex-determination mechanisms among reptiles, it is apparent that transitions between modes have occurred many times, as they have for amphibians (particularly between male and female heterogamety). It is also likely that thermosensitivity in sex determination is a key factor in those transitions in reptiles, and possibly in amphibians too. New models of sex determination involving temperature thresholds are providing the framework for the investigation of transitions and making possible key predictions about the homologies and sex-determination patterns expected among taxa in these groups. Molecular cytogenetics and other genomic approaches are essential to providing the fundamental material necessary to make advances in this field.
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Affiliation(s)
- Stephen D Sarre
- Wildlife Genetics Laboratory, Institute for Applied Ecology, University of Canberra, ACT 2601, Australia.
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Yaklichkin SY, Darnell DK, Pier MV, Antin PB, Hannenhalli S. Accelerated evolution of 3'avian FOXE1 genes, and thyroid and feather specific expression of chicken FoxE1. BMC Evol Biol 2011; 11:302. [PMID: 21999483 PMCID: PMC3207924 DOI: 10.1186/1471-2148-11-302] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2011] [Accepted: 10/15/2011] [Indexed: 12/04/2022] Open
Abstract
Background The forkhead transcription factor gene E1 (FOXE1) plays an important role in regulation of thyroid development, palate formation and hair morphogenesis in mammals. However, avian FOXE1 genes have not been characterized and as such, codon evolution of FOXE1 orthologs in a broader evolutionary context of mammals and birds is not known. Results In this study we identified the avian FOXE1 gene in chicken, turkey and zebra finch, all of which consist of a single exon. Chicken and zebra finch FOXE1 are uniquely located on the sex-determining Z chromosome. In situ hybridization shows that chicken FOXE1 is specifically expressed in the developing thyroid. Its expression is initiated at the placode stage and is maintained during the stages of vesicle formation and follicle primordia. Based on this expression pattern, we propose that avian FOXE1 may be involved in regulating the evagination and morphogenesis of thyroid. Chicken FOXE1 is also expressed in growing feathers. Sequence analysis identified two microdeletions in the avian FOXE1 genes, corresponding to the loss of a transferable repression domain and an engrailed homology motif 1 (Eh1) C-terminal to the forkhead domain. The avian FOXE1 proteins exhibit a significant sequence divergence of the C-terminus compared to those of amphibian and mammalian FOXE1. The codon evolution analysis (dN/dS) of FOXE1 shows a significantly increased dN/dS ratio in the avian lineages, consistent with either a relaxed purifying selection or positive selection on a few residues in avian FOXE1 evolution. Further site specific analysis indicates that while relaxed purifying selection is likely to be a predominant cause of accelerated evolution at the 3'-region of avian FOXE1, a few residues might have evolved under positive selection. Conclusions We have identified three avian FOXE1 genes based on synteny and sequence similarity as well as characterized the expression pattern of the chicken FOXE1 gene during development. Our evolutionary analyses suggest that while a relaxed purifying selection is likely to be the dominant force driving accelerated evolution of avian FOXE1 genes, a few residues may have evolved adaptively. This study provides a basis for future genetic and comparative biochemical studies of FOXE1.
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Affiliation(s)
- Sergey Yu Yaklichkin
- Penn Center for Bioinformatics, 1424 Blockley Hall, 423 Guardian Drive, University of Pennsylvania, Philadelphia, PA 19104 USA
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Nakamura M. The mechanism of sex determination in vertebrates-are sex steroids the key-factor? ACTA ACUST UNITED AC 2010; 313:381-98. [PMID: 20623803 DOI: 10.1002/jez.616] [Citation(s) in RCA: 105] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
In many vertebrate species, sex is determined at fertilization of zygotes by sex chromosome composition, knows as genotypic sex determination (GSD). But in some species-fish, amphibians and reptiles-sex is determined by environmental factors; in particular by temperature-dependent sex determination (TSD). However, little is known about the mechanisms involved in TSD and GSD. How does TSD differ from GSD? As is well known, genes that activated downstream of sex-determining genes are conserved throughout all classes of vertebrates. What is the main factor that determines sex, then? Sex steroids can reverse sex of several species of vertebrate; estrogens induce the male-to-female sex-reversal, whereas androgens do the female-to-male sex-reversal. For such sex-reversal, a functioning sex-determining gene is not required. However, in R. rugosa CYP19 (P450 aromatase) is expressed at high levels in indifferent gonads before phenotypic sex determination, and the gene is also active in the bipotential gonad of females before sex determination. Thus, we may predict that an unknown factor, a common transcription factor locates on the X and/or W chromosome, intervenes directly or indirectly in the transcriptional up-regulation of the CYP19 gene for feminization in species of vertebrates with both TSD and GSD. Similarly, an unknown factor on the Z and/or Y chromosome probably intervenes directly or indirectly in the regulation of androgen biosynthesis for masculinization. In both cases, a sex-determining gene is not always necessary for sex determination. Taken together, sex steroids may be the key-factor for sex determination in some species of vertebrates.
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Affiliation(s)
- Masahisa Nakamura
- Department of Biology, Faculty of Education and Integrated Arts and Sciences, Waseda University, Shinjuku-ku, Tokyo, Japan.
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Hou Y, Zhou X, Liu J, Yuan J, Cheng H, Zhou R. Nuclear factor-Y (NF-Y) regulates transcription of mouse Dmrt7 gene by binding to tandem CCAAT boxes in its proximal promoter. Int J Biol Sci 2010; 6:655-64. [PMID: 21060727 PMCID: PMC2974168 DOI: 10.7150/ijbs.6.655] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2010] [Accepted: 10/23/2010] [Indexed: 02/01/2023] Open
Abstract
Dmrt7, a member of the Dmrt family of genes, is required for spermatogenesis. However, promoter functions of the gene Dmrt7 remain unknown. We have cloned and characterized the proximal promoter region of the mouse Dmrt7 gene. Functional analysis of the 5' flanking region by sequential deletion mutations revealed crucial positive elements between -60 and +1, in which two highly conserved and tandem CCAAT boxes: the CCAAT box1 (-48/-44) and the CCAAT box2 (-7/-3) are located. Site-directed mutagenesis studies demonstrated that both CCAAT boxes are indispensable to the promoter activity. Electrophoretic mobility shift assays (EMSAs) and gel-supershift assays indicated that transcription factor NF-Y binds to the promoter. Chromatin immunoprecipitation (ChIP) analysis demonstrated that NF-Y interacts in vivo with the promoter of the Dmrt7 gene in testis. Co-transfection and reporter analysis showed that over-expression of NF-Ys increased transcription of the Dmrt7-luc gene whereas expression of a dominant-negative NF-Ya decreased the transcription. This suggests that NF-Y can activate the Dmrt7 promoter. These results provide evidence of a transcription regulatory mechanism that controls Dmrt7 gene expression in mouse testis.
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Affiliation(s)
- Yu Hou
- Department of Genetics, College of Life Sciences, Wuhan University, Wuhan 430072, PR China
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Lin YP, Chen LR, Chen CF, Liou JF, Chen YL, Yang JR, Shiue YL. Identification of early transcripts related to male development in chicken embryos. Theriogenology 2010; 74:1161-1178.e1-8. [PMID: 20728927 DOI: 10.1016/j.theriogenology.2010.05.017] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2009] [Revised: 05/08/2010] [Accepted: 05/15/2010] [Indexed: 01/21/2023]
Abstract
Early transcripts related to male development in chicken embryos and their expression profiles were examined. A total of 89 and 127 candidate male development transcripts that represented 83 known and 119 unknown non-redundant sequences, respectively, were characterized in an embryonic day 3 (E3; Hamburger and Hamilton Stage 20: HH20) male-subtract-female complementary DNA library. Of 35 selected transcripts, quantitative reverse transcription-polymerase chain reaction validated that the expression levels of 25 transcripts were higher in male E3 whole embryos than in females (P < 0.05). Twelve of these transcripts mapped to the Z chromosome. At 72 wk of age, 20 and 4 transcripts were expressed at higher levels in the testes and brains of male than in the ovaries and brains of female chickens (P < 0.05), respectively. Whole mount and frozen cross-section in situ hybridization, as well as Western blotting analysis further corroborated that riboflavin kinase (RFK), WD repeat domain 36 (WDR36), and EY505808 transcripts; RFK and WDR36 protein products were predominantly expressed in E7 male gonads. Treatment with an aromatase inhibitor formestane at E4 affected the expression levels at E7 of the coatomer protein complex (subunit beta 1), solute carrier family 35 member F1, LOC427316 and EY505812 transcripts across both sexes (P < 0.05), similar to what was observed for the doublesex and mab-3 related transcription factor 1 gene. The interaction effects of sex by formestane treatment were observed in 15 candidate male development transcripts (P < 0.05). Taken together, we identified a panel of potentially candidate male development transcripts during early chicken embryogenesis; some might be regulated by sex hormones.
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Affiliation(s)
- Yuan-Ping Lin
- Institute of Biomedical Science, National Sun Yat-sen University, Kaohsiung, Taiwan
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Liu ZH, Zhang YG, Wang DS. Studies on feminization, sex determination, and differentiation of the Southern catfish, Silurus meridionalis--a review. FISH PHYSIOLOGY AND BIOCHEMISTRY 2010; 36:223-235. [PMID: 19002765 DOI: 10.1007/s10695-008-9281-7] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2008] [Accepted: 10/13/2008] [Indexed: 05/27/2023]
Abstract
The sex ratio of the feral Southern catfish was reported to be about 1:1, while the fish obtained by artificial fertilization were always female. Hence, we examined the possible influence of the micro-environment during artificial insemination (pH of the ovarian fluid and concentration of the semen) and early development (feed, hatching temperature, and water) on the sex ratio of Southern catfish fry. In order to examine the possibility of the occurrence of gynogenesis during artificial propagation, cytological observations on the insemination processes and the artificial induction of gynogenesis were also performed. However, no male fish were obtained even in these experiments, excluding the possibilities of these micro-environmental changes on catfish sex ratio and the occurrence of gynogenesis during artificial propagation. Female-to-male sex reversal was achieved by treatment with fadrozole (an aromatase inhibitor) and tamoxifen (an estrogen receptor antagonist). Histological analyses on the gonadal development of both female and induced male fish were subsequently performed. Moreover, several genes involved in sex differentiation, such as dmrt1, foxl2, and cyp19, and three subunits of gonadotropin (gth), i.e., gthalpha, lhbeta, and fshbeta, were isolated. Their expression patterns were studied under normal gonadal development and sex reversal conditions. The results revealed that dmrt1, foxl2, and cyp19a were closely related to catfish sex differentiation, and the gth subunits were possibly related to ovarian differentiation and oocyte development. Taken together, we hypothesized that estrogen was highly responsible for the ovarian differentiation and feminization of catfish fry under artificial propagation, although the mechanism involved remains elusive.
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Affiliation(s)
- Z H Liu
- Key Laboratory of Eco-environments in Three Gorges Reservoir Region (Ministry of Education), School of Life Science, Southwest University, Chongqing 400715, China
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Kim JE, Bauer MM, Mendoza KM, Reed KM, Coulombe RA. Comparative genomics identifies new alpha class genes within the avian glutathione S-transferase gene cluster. Gene 2010; 452:45-53. [DOI: 10.1016/j.gene.2009.11.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2009] [Revised: 11/02/2009] [Accepted: 11/03/2009] [Indexed: 11/29/2022]
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Leder EH, Cano JM, Leinonen T, O'Hara RB, Nikinmaa M, Primmer CR, Merilä J. Female-biased expression on the X chromosome as a key step in sex chromosome evolution in threespine sticklebacks. Mol Biol Evol 2010; 27:1495-503. [PMID: 20142438 DOI: 10.1093/molbev/msq031] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Given that the genome of males and females are almost identical with the exception of genes on the Y (or W) chromosome or sex-determining alleles (in organisms without sex chromosomes), it is likely that many downstream processes resulting in sexual dimorphism are produced by changes in regulation. In early stages of sex chromosome evolution, as the Y-chromosome degenerates, gene expression should be significantly impacted for genes residing on the sex chromosome pair as regulatory mutations accumulate. However, this has rarely been examined because most model organisms have clearly diverged sex chromosomes. Fish provide a unique opportunity to examine the evolution of sex chromosomes because genetic sex determination has evolved quite recently in some groups of fish. We compared sex-specific transcription in threespine stickleback (Gasterosteus aculeatus) liver tissue using a long-oligo microarray. Of the 1,268 genes that were differentially expressed between sexes, a highly significant proportion (23%) was concentrated on chromosome 19, corresponding to the recently described nascent sex chromosomes. The sex-biased genes are enriched for different functional categories in males and females, although there is no specific functional enrichment on the sex chromosomes. Female-biased genes are concentrated at one end of the sex chromosome, corresponding to a deletion in the Y, suggesting a lack of global dosage compensation. Prior research on threespine sticklebacks has demonstrated various degrees of dissimilarity in upstream regions of genes on the Y providing a potential mechanism for the observed patterns of female-biased expression. We hypothesize that degeneration of the Y chromosome results in regulatory mutations that create a sex-specific expression pattern and that this physical concentration of sex-biased expression on the nascent sex chromosome may be a key feature characterizing intermediate phases of sex chromosome evolution.
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Affiliation(s)
- Erica H Leder
- Division of Genetics and Physiology, Department of Biology (Vesilinnantie 5), University of Turku, Turku, Finland.
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Kemkemer C, Kohn M, Kehrer-Sawatzki H, Fundele RH, Hameister H. Enrichment of brain-related genes on the mammalian X chromosome is ancient and predates the divergence of synapsid and sauropsid lineages. Chromosome Res 2009; 17:811-20. [PMID: 19731051 DOI: 10.1007/s10577-009-9072-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2009] [Revised: 08/06/2009] [Accepted: 08/07/2009] [Indexed: 01/26/2023]
Abstract
Previous studies have revealed an enrichment of reproduction- and brain-related genes on the human X chromosome. In the present study, we investigated the evolutionary history that underlies this functional specialization. To do so, we analyzed the orthologous building blocks of the mammalian X chromosome in the chicken genome. We used Affymetrix chicken genome microarrays to determine tissue-selective gene expression in several tissues of the chicken, including testis and brain. Subsequently, chromosomal distribution of genes with tissue-selective expression was determined. These analyzes provided several new findings. Firstly, they showed that chicken chromosomes orthologous to the mammalian X chromosome exhibited an increased concentration of genes expressed selectively in brain. More specifically, the highest concentration of brain-selectively expressed genes was found on chicken chromosome GGA12, which shows orthology to the X chromosomal regions with the highest enrichment of non-syndromic X-linked mental retardation (MRX) genes. Secondly, and in contrast to the first finding, no enrichment of testis-selective genes could be detected on these chicken chromosomes. These findings indicate that the accumulation of brain-related genes on the prospective mammalian X chromosome antedates the divergence of sauropsid and synapsid lineages 315 million years ago, whereas the accumulation of testis-related genes on the mammalian X chromosome is more recent and due to adaptational changes.
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Affiliation(s)
- Claus Kemkemer
- Institute of Human Genetics, University of Ulm, Ulm, Germany
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Karyotypic evolution in squamate reptiles: comparative gene mapping revealed highly conserved linkage homology between the butterfly lizard (Leiolepis reevesii rubritaeniata, Agamidae, Lacertilia) and the Japanese four-striped rat snake (Elaphe quadrivirgata, Colubridae, Serpentes). Chromosome Res 2009; 17:975-86. [PMID: 19937109 DOI: 10.1007/s10577-009-9101-7] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2009] [Accepted: 11/01/2009] [Indexed: 10/20/2022]
Abstract
The butterfly lizard (Leiolepis reevesii rubritaeniata) has the diploid chromosome number of 2n = 36, comprising two distinctive components, macrochromosomes and microchromosomes. To clarify the conserved linkage homology between lizard and snake chromosomes and to delineate the process of karyotypic evolution in Squamata, we constructed a cytogenetic map of L. reevesii rubritaeniata with 54 functional genes and compared it with that of the Japanese four-striped rat snake (E. quadrivirgata, 2n = 36). Six pairs of the lizard macrochromosomes were homologous to eight pairs of the snake macrochromosomes. The lizard chromosomes 1, 2, 4, and 6 corresponded to the snake chromosomes 1, 2, 3, and Z, respectively. LRE3p and LRE3q showed the homology with EQU5 and EQU4, respectively, and LRE5p and LRE5q corresponded to EQU7 and EQU6, respectively. These results suggest that the genetic linkages have been highly conserved between the two species and that their karyotypic difference might be caused by the telomere-to-telomere fusion events followed by inactivation of one of two centromeres on the derived dicentric chromosomes in the lineage of L. reevesii rubritaeniata or the centric fission events of the bi-armed macrochromosomes and subsequent centromere repositioning in the lineage of E. quadrivirgata. The homology with L. reevesii rubritaeniata microchromosomes were also identified in the distal regions of EQU1p and 1q, indicating the occurrence of telomere-to-telomere fusions of microchromosomes to the p and q arms of EQU1.
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Sato Y, Shinka T, Sakamoto K, Ewis AA, Nakahori Y. The male-determining gene SRY is a hybrid of DGCR8 and SOX3, and is regulated by the transcription factor CP2. Mol Cell Biochem 2009; 337:267-75. [PMID: 19902333 DOI: 10.1007/s11010-009-0308-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2009] [Accepted: 10/29/2009] [Indexed: 11/24/2022]
Abstract
In mammals, sex is determined by the presence or absence of the Y chromosome that bears a male-dominant sex-determining gene SRY, which switches the differentiation of gonads into male testes. The molecular signaling mechanism turning on the switch, however, has remained unclear for 18 years since the identification of the gene. Here, we describe how this gene emerged and started to work. From amino acid homology, we realized that SRY is a hybrid gene between a portion of the first exon of DiGeorge syndrome critical region gene 8 (DGCR8) and the high-mobility group (HMG) box of SRY box-3 (SOX3) gene. We identified the regulatory sequence in the SRY promotor region by searching for a common motif shared with DGCR8 mRNA. From the motif search between DGCR8 mRNA and the SRY upstream sequence, we found that the transcription factor CP2 (TFCP2) binding motif is present in both. TFCP2 overexpression did not show a significant increase of SRY mRNA expression, and TFCP2 suppression by RNA interference (RNAi) significantly reduced SRY mRNA expression. Furthermore, electrophoretic mobility shift assay (EMSA) demonstrated that TFCP2 acts as a regulator by directly binding to the SRY promoter. We conclude that SRY is a hybrid gene composed of two genes, DGCR8 and SOX3; and TFCP2 is an essential transcription factor for SRY expression regulation.
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Affiliation(s)
- Youichi Sato
- Department of Human Genetics and Public Health, Institute of Health Biosciences, The University of Tokushima Graduate School, Tokushima, Japan.
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Schneider WJ. Receptor-mediated mechanisms in ovarian follicle and oocyte development. Gen Comp Endocrinol 2009; 163:18-23. [PMID: 19523388 DOI: 10.1016/j.ygcen.2008.11.032] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2008] [Revised: 11/26/2008] [Accepted: 11/27/2008] [Indexed: 11/21/2022]
Abstract
The normal development of the chicken oocyte within the ovarian follicle depends on the coordinated expression and function of several members of the low density lipoprotein receptor gene family. The human low density lipoprotein receptor (LDLR) is the prototype of the gene family; since its discovery and the elucidation of the medical significance of mutations in the ldlr gene, many additional family members have been discovered and characterized, and some important advances have resulted from studies in the chicken. I describe the analogies as well as the differences that exist between the molecular genetics of the mammalian and avian members of this important gene family, with emphasis on receptor-mediated oocyte growth. Recent progress in the molecular characterization of the chicken genes whose products mediate oocyte growth, follicle development, and accessory pathways is described in detail, and emerging information of preliminary nature is included. As the availability of chicken genome sequence data has enhanced the rate of progress in the field, our understanding of the physiological roles of members of this receptor family in general has already gained from studies in the avian model system.
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Affiliation(s)
- Wolfgang J Schneider
- Department of Medical Biochemistry, Max F. Perutz Laboratories, Medical University of Vienna, Dr. Bohr Gasse 9/2, A-1030 Vienna, Austria.
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The avian Z-linked gene DMRT1 is required for male sex determination in the chicken. Nature 2009; 461:267-71. [DOI: 10.1038/nature08298] [Citation(s) in RCA: 599] [Impact Index Per Article: 39.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2009] [Accepted: 07/21/2009] [Indexed: 01/09/2023]
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44
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Hulsey CD. Cichlid genomics and phenotypic diversity in a comparative context. Integr Comp Biol 2009; 49:618-29. [DOI: 10.1093/icb/icp071] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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45
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Pala I, Schartl M, Thorsteinsdóttir S, Coelho MM. Sex determination in the Squalius alburnoides complex: an initial characterization of sex cascade elements in the context of a hybrid polyploid genome. PLoS One 2009; 4:e6401. [PMID: 19636439 PMCID: PMC2713423 DOI: 10.1371/journal.pone.0006401] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2009] [Accepted: 06/22/2009] [Indexed: 11/19/2022] Open
Abstract
Background Sex determination processes vary widely among different vertebrate taxa, but no group offers as much diversity for the study of the evolution of sex determination as teleost fish. However, the knowledge about sex determination gene cascades is scarce in this species-rich group and further difficulties arise when considering hybrid fish taxa, in which mechanisms exhibited by parental species are often disrupted. Even though hybridisation is frequent among teleosts, gene based approaches on sex determination have seldom been conducted in hybrid fish. The hybrid polyploid complex of Squalius alburnoides was used as a model to address this question. Methodology/Principal Findings We have initiated the isolation and characterization of regulatory elements (dmrt1, wt1, dax1 and figla) potentially involved in sex determination in S. alburnoides and in the parental species S. pyrenaicus and analysed their expression patterns by in situ hybridisation. In adults, an overall conservation in the cellular localization of the gene transcripts was observed between the hybrids and parental species. Some novel features emerged, such as dmrt1 expression in adult ovaries, and the non-dimorphic expression of figla, an ovarian marker in other species, in gonads of both sexes in S. alburnoides and S. pyrenaicus. The potential contribution of each gene to the sex determination process was assessed based on the timing and location of expression. Dmrt1 and wt1 transcripts were found at early stages of male development in S. alburnoides and are most likely implicated in the process of gonad development. Conclusions/Significance For the first time in the study of this hybrid complex, it was possible to directly compare the gene expression patterns between the bisexual parental species and the various hybrid forms, for an extended set of genes. The contribution of these genes to gonad integrity maintenance and functionality is apparently unaltered in the hybrids, suggesting that no abrupt shifts in gene expression occurred as a result of hybridisation.
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Affiliation(s)
- Irene Pala
- Centro de Biologia Ambiental, Departamento de Biologia Animal, Faculdade de Ciências da Universidade de Lisboa, Lisbon, Portugal.
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Smith JJ, Voss SR. Amphibian sex determination: segregation and linkage analysis using members of the tiger salamander species complex (Ambystoma mexicanum and A. t. tigrinum). Heredity (Edinb) 2009; 102:542-8. [PMID: 19259115 PMCID: PMC2684942 DOI: 10.1038/hdy.2009.15] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Little is known about the genetic basis of sex determination in vertebrates though considerable progress has been made in recent years. In this study, segregation analysis and linkage mapping were performed to localize an amphibian sex-determining locus (ambysex) in the tiger salamander (Ambystoma) genome. Segregation of sex phenotypes (male and female) among the second generation individuals of interspecific crosses (Ambystoma mexicanum x Ambystoma tigrinum tigrinum) was consistent with Mendelian expectations, although a slight female bias was observed. Individuals from these same crosses were typed for single-nucleotide polymorphisms distributed throughout the genome to identify molecular markers for ambysex. A marker (E24C3) was identified approximately 5.9 cM from ambysex. Linkage of E24C3 to ambysex was independently validated in a second, intraspecific cross (A. mexicanum). Interestingly, ambysex locates to the tip of one of the larger linkage groups of the Ambystoma meiotic map. Considering that this location does not show reduced recombination, we speculate that the ambysex locus may have arisen quite recently, within the last few million years. Localization of ambysex sets the stage for gene identification and provides important tools for studying the effect of sex in laboratory and natural populations of this model amphibian system.
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Affiliation(s)
- J J Smith
- Department of Biology and Spinal Cord, Brian Injury Research Center, University of Kentucky, Lexington, KY, USA.
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Isolation and characterization of DMRT1 and its putative regulatory region in the protogynous wrasse, Halichoeres tenuispinis. Gene 2009; 438:8-16. [DOI: 10.1016/j.gene.2009.03.006] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2008] [Revised: 02/20/2009] [Accepted: 03/09/2009] [Indexed: 11/19/2022]
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48
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Delbridge ML, Patel HR, Waters PD, McMillan DA, Marshall Graves JA. Does the human X contain a third evolutionary block? Origin of genes on human Xp11 and Xq28. Genome Res 2009; 19:1350-60. [PMID: 19439513 DOI: 10.1101/gr.088625.108] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Comparative gene mapping of human X-borne genes in marsupials defined an ancient conserved region and a recently added region of the eutherian X, and the separate evolutionary origins of these regions was confirmed by their locations on chicken chromosomes 4p and 1q, respectively. However, two groups of genes, from the pericentric region of the short arm of the human X (at Xp11) and a large group of genes from human Xq28, were thought to be part of a third evolutionary block, being located in a single region in fish, but mapping to chicken chromosomes other than 4p and 1q. We tested this hypothesis by comparative mapping of genes in these regions. Our gene mapping results show that human Xp11 genes are located on the marsupial X chromosome and platypus chromosome 6, indicating that the Xp11 region was part of original therian X chromosome. We investigated the evolutionary origin of genes from human Xp11 and Xq28, finding that chicken paralogs of human Xp11 and Xq28 genes had been misidentified as orthologs, and their true orthologs are represented in the chicken EST database, but not in the current chicken genome assembly. This completely undermines the evidence supporting a separate evolutionary origin for this region of the human X chromosome, and we conclude, instead, that it was part of the ancient autosome, which became the conserved region of the therian X chromosome 166 million years ago.
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Affiliation(s)
- Margaret L Delbridge
- The ARC Centre of Excellence for Kangaroo Genomics, Research School of Biological Sciences, The Australian National University, ACT Australia.
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49
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Alekseevich LA, Lukina NA, Nikitin NS, Nekrasova AA, Smirnov AF. Problems of sex determination in birds exemplified by Gallus gallus domesticus. RUSS J GENET+ 2009. [DOI: 10.1134/s1022795409030016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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