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Ramachandra NB, Ranganath HA. The chromosomes of two Drosophila races: Drosophila nasuta nasuta and Drosophila nasuta albomicana V. Introgression and the evolution of new karyotypes. J ZOOL SYST EVOL RES 2009. [DOI: 10.1111/j.1439-0469.1990.tb00365.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Ramachandra NB, Ranganath HA. Estimation of inter-genotypic competitive ability of the parental races (Drosophila nasuta nasuta and D. n. albomicana) and of the newly evolved Cytoraces (I and II). J ZOOL SYST EVOL RES 2009. [DOI: 10.1111/j.1439-0469.1994.tb00472.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Nagaraju J, Ranganath HA. Molecular phylogeny of the nasuta subgroup of Drosophila based on 12S rRNA, 16S rRNA and CoI mitochondrial genes, RAPD and ISSR polymorphisms. Genes Genet Syst 2004; 79:293-9. [PMID: 15599059 DOI: 10.1266/ggs.79.293] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
The nasuta subgroup is a cluster of morphologically almost similar forms with a wide range of geographic distribution. During the last three decades nature of inter-relationship among the members has been investigated at different levels of organization. The phylogenetic relationships of the members of the nasuta subgroup of the immigrans species group of Drosophila was made by employing Random Amplified Polymorphic DNA (RAPD), Inter Simple Sequence Repeats-PCR (ISSR-PCR) polymorphisms, mitochondrial 12S rRNA, 16S rRNA and Cytochrome C Oxidase subunit I (CoI) gene sequences. The phylogenetic tree generated by RAPD analysis is in nearly complete congruence with the classification based on morphophenotypic characters. The 12S and 16S rRNA genes were highly conserved across the nasuta subgroup and revealed only 3 and 4 variable sites respectively, of which only one site was informative. The CoI gene, on the other hand, revealed 57 variable sites of which 25 sites were informative. All the three species of orbital sheen complex were included in a major cluster in the phylogenetic trees derived from mitochondrial gene sequence data consistent with the morphophenotypic classification. The CoI analysis placed two species of frontal sheen complex, D. n. nasuta and D. n. albomicans in two different clades and this is inconsistent with morphological classification. The molecular clock suggested that divergence between the kohkoa complex and the albomicans complex occurred approximately 2.2 MYA, indicating recent evolution of the nasuta subgroup. The higher transition bias in the mitochondrial genes reported in the present study also suggested recent evolution of the nasuta subgroup.
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Ranganath HA, Aruna S. Hybridization, transgressive segregation and evolution of new genetic systems inDrosophila. J Genet 2003; 82:163-77. [PMID: 15133193 DOI: 10.1007/bf02715816] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Introgressive hybridization facilitates incorporation of genes from one species into the gene pool of another. Studies on long-term effects of introgressive hybridization in animal systems are sparse. Drosophila nasuta (2n = 8) and D. albomicans (2n = 6)-a pair of allopatric, morphologically almost identical, cross-fertile members of the nasuta subgroup of the immigrans species group-constitute an excellent system to analyse the impact of hybridization followed by transgressive segregation of parental characters in the hybrid progeny. Hybrid populations of D. nasuta and D. albomicans maintained for over 500 generations in the laboratory constitute new recombinant hybrid genomes, here termed cytoraces. The impact of hybridization, followed by introgression and transgressive segregation, on chromosomal constitution and karyotypes, some fitness parameters, isozymes, components of mating behaviour and mating preference reveals a complex pattern of interracial divergence among parental species and cytoraces. This assemblage of characters in different combinations in a laboratory hybrid zone allows us to study the emergence of new genetic systems. Here, we summarize results from our ongoing studies comparing these hybrid cytoraces with the parental species, and discuss the implications of these findings for our understanding of the evolution of new genetic systems.
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Affiliation(s)
- H A Ranganath
- Drosophila Stock Centre, Department of Studies in Zoology, University of Mysore, Manasagangotri, Mysore 570 006, India.
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Tanuja MT, Ramachandra NB, Ranganath HA. Hybridization and introgression of the genomes of Drosophila nasuta and Drosophila albomicans: evolution of new karyotypes. Genome 2003; 46:605-11. [PMID: 12897869 DOI: 10.1139/g03-039] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Drosophila nasuta (2n = 8) and Drosophila albomicans (2n = 6) are cross-fertile allopatric sibling chromosomal races of the nasuta subgroup of Drosophila. Hybrids of these races can be maintained for any number of generations. Some of the introgressed hybrid lineages of D. nasuta and D. albomicans, after passing through a transient phase of karyotypic polymorphism, ended up with a stable karyotype whose composition is different from those of the parental races. Such hybrid populations were called cytoraces, in which the chromosomes of D. nasuta and D. albomicans are represented in different combinations. The karyotypic composition of 16 such cytoraces have been presented and discussed with reference to evolutionary strategies such as balancing selection, directional selection, and sex-specific effect on different components of the evolving karyotypes.
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Affiliation(s)
- M T Tanuja
- Drosophila Stock Centre, Departemnt of Studies in Zoology, University of Mysore, Manasagangotry, Mysore, India
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Mahesh G, Ramachandra NB, Ranganath HA. Autoradiographic study of transcription and dosage compensation in the sex and neo-sex chromosome of Drosophila nasuta nasuta and Drosophila nasuta albomicans. Genome 2001. [DOI: 10.1139/g00-100] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cellular autoradiography is used to study the transcription patterns of the polytene X chromosomes in Drosophila nasuta nasuta and D. n. albomicans. D. n. nasuta, with 2n = 8, includes a pair of complete heteromorphic sex chromosomes, whereas D. n. albomicans, with 2n = 6, has a pair of metacentric neo-sex chromosomes representing incomplete heteromorphic sex chromosomes. The neo-X chromosome has two euchromatic arms, one representing the ancestral X while the other represents the ancestral autosome 3 chromosomes. The metacentric neo-Y chromosome has one arm with a complete heterochromatic ancestral Y and the other arm with a euchromatic ancestral autosome 3. The transcription study has revealed that the X chromosome in D. n. nasuta is hyperactive, suggesting complete dosage compensation, while in the neo-X chromosome of D. n. albomicans the ancestral X chromosome is hyperactive and the ancestral autosome 3, which is part of the neo-sex chromosome, is similar to any other autosomes. This finding shows dosage compensation on one arm (XLx/) of the neo-X chromosome, while the other arm (XR3/YR3) is not dosage compensated and has yet to acquire the dosage compensatory mechanism.Key words: Drosophila, chromosomal races, neo-sex chromosome, transcription and dosage compensation.
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Evolution of a new chromosomal lineage in a laboratory population ofDrosophila through centric fission. J Biosci 1999. [DOI: 10.1007/bf02942651] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Zhimulev IF. Polytene chromosomes, heterochromatin, and position effect variegation. ADVANCES IN GENETICS 1997; 37:1-566. [PMID: 9352629 DOI: 10.1016/s0065-2660(08)60341-7] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- I F Zhimulev
- Institute of Cytology and Genetics, Siberian Division of the Russian Academy of Sciences, Novosibirsk, Russia
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Obara Y, Sasaki S, Igarashi Y. Delayed response of QM- and DA/DAPI-fluorescence in C-heterochromatin of the small Japanese field mouse, Apodemus argenteus. Zoolog Sci 1997; 14:57-64. [PMID: 9200979 DOI: 10.2108/zsj.14.57] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The small Japanese field mouse Apodemus argenteus has the diploid chromosome number of 46, carrying rather large centromeric C-heterochromatin in most of the 44 autosomes and a large amount of C-heterochromatin in the sex chromosomes: the largest subtelocentric X was heterochromatic in almost two-fifth (whole short arm and proximal part of the long arm) of its entire length and the medium-sized acrocentric Y was totally heterochromatic. The C-heterochromatin (C-positive) areas, other than those of the Y and smallest three pairs, had a unique property of "delayed QM-fluorescence", which has not been reported to-date, showing dull QM-fluorescence immediately after exposure to blue light (BL), but gradually turning to bright fluorescence in a few minutes. The fluorescence intensity gradually decreased after attaining its peak, and finally became extinct. A similar pattern of fluorescence was also obtained in DA/DAPI-stained-X chromosome C-heterochromatin, but not in autosomal C-heterochromatin. No such dull-to-bright transition of QM-fluorescence could be obtained by CMA staining, for which the C-positive areas were apparently negative even after overexposure to BL. These facts indicate that the C-positive areas of A. argenteus showing dull-to-bright transition of QM-fluorescence contain A-T rich DNA. The delayed QM-fluorescence was found only in A. argenteus, in thirteen mammalian species so-far examined. Furthermore, this unique property of QM-fluorescence could be artificially altered to non-delayed ordinary type of fluorescence by sequentially pretreating the fixed chromosomes with hydrochloride and barium hydroxide solutions. The cytological implication of the delayed fluorescence in the C-heterochromatin of A. argenteus is briefly discussed.
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Affiliation(s)
- Y Obara
- Department of Biology, Faculty of Science, Hirosaki University, Aomori, Japan
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Tiwari PK, Lakhotia SC. Restriction enzyme digestion of heterochromatin inDrosophila nasuta. J Biosci 1991. [DOI: 10.1007/bf02703284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Rao PM, Ranganath HA. Karyotype differentiation among members of the immigrans species group of Drosophila. Genetica 1991; 83:145-52. [PMID: 2026329 DOI: 10.1007/bf00058531] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Karyotypes of ten species belonging to four of the five subgroups of the immigrans species group of Drosophila were examined. The group includes species with the most primitive form of karyotype as well as species with so-called recent karyotypic configurations. It is an assemblage of species with karyotypes representing five of the six successive stages involved in the evolution from 2n = 12 to 2n = 6. Implications of these findings are discussed.
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Affiliation(s)
- P M Rao
- Department of Post-graduate Studies and Research in Zoology, University of Mysore, Manasa Gangotri, India
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Rao PM, Ranganath HA. An allozyme phylogeny of some members of the immigrans species group of Drosophila. Genetica 1990; 82:177-81. [PMID: 2090558 DOI: 10.1007/bf00056360] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Allozyme variations at ten loci, in a few species belonging to four different subgroups of the immigrans species group have been studied. The biochemical phylogeny of these species revealed two main lineages. In one of these main lineages, D. n. nasuta, D. n. albomicans and D. s. neonasuta constitute one group while D. immigrans and D. formosana comprise another group. The other main lineage includes D. rubida, D. pararubida, D. hypocausta and D. lineosa.
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Affiliation(s)
- P M Rao
- Department of Studies in Zoology, University of Mysore, Manasagangotri, India
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Kumar A, Gupta JP. Interrelationships among three derivative forms of the immigrans-Hirtodrosophila radiation: evidence from heterochromatin and polytene chromosomes. Genetica 1987. [DOI: 10.1007/bf00056031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Characterization of heterochromatin in the B chromosomes of Drosophila nasuta albomicana. Chromosoma 1987. [DOI: 10.1007/bf00330354] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Sumner AT. Mechanisms of quinacrine binding and fluorescence in nuclei and chromosomes. HISTOCHEMISTRY 1986; 84:566-74. [PMID: 3721920 DOI: 10.1007/bf00482993] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The mechanisms has been investigated whereby quinacrine binds to the DNA of nuclei and chromosomes in cytological preparations fixed in methanol-acetic acid. A variety of evidence is consistent with the idea that the quinacrine binds by intercalation. This is supported by a high value for the affinity of quinacrine for DNA, together with a saturation value of 0.2 quinacrine molecules/nucleotide; binding in the presence of strong salt solutions; and inhibition of fluorescence and banding by denaturation or depurination of DNA. At high quinacrine concentrations, weak binding of quinacrine to nuclei and chromosomes also occurs, but this is not relevant to the production of strong fluorescence or Q-banding patterns. A number of factors were tested which might have affected quinacrine fluorescence and banding. These included: pH; blocking protein amino groups by acetylation or benzoylation; introduction of hydrophobic groups by benzoylation; and dephosphorylation. All these treatments were without effect. However, comparison of the quinacrine fluorescence of human and onion nuclei, which differ substantially in the base composition of their DNA, shows that quinacrine fluorescence can be enhanced in cytological preparations by AT-rich DNA.
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Ramachandra NB, Ranganath HA. The chromosomes of two Drosophila races: D. nasuta nasuta and D. nasuta albomicana. Chromosoma 1986. [DOI: 10.1007/bf00292744] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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H�gele K, Ranganath HA. The chromosomes of two Drosophila races: D. nasuta nasuta and D. nasuta albomicans III. Localization of nucleolar organizer regions. Genetica 1983. [DOI: 10.1007/bf00127498] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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