Simple repetitive sequences are associated with differentiation of the sex chromosomes in the guppy fish
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Hybridization of restriction enzymedigested genomic guppy (Poecilia reticulata, Poeciliidae) DNA with the oligonucleotide probe (GACA)4 revealed a male-specific simple tandem repeat locus, which defines the Y chromosome in outbred populations. The related (GATA)4 probe identifies certain males with the red color phenotype. In contrast only in two out of eight laboratory guppy strains was the typical (GACA)4 band observed. By specific staining of the constitutive heterochromatin one pair of chromosomes could also be identified as the sex chromosomes, confirming the XX/XY mechanism of sex determination. All males exhibit Y chromosomes with a large region of telomeric heterochromatin. Hybridization in situ with nonradioactively labeled oligonucleotide probes localized the (GACA)n repeats to this heterochromatic portion. Together these results may be regarded as a recent paradigm for the differentiation of heteromorphic sex chromosomes from a pair of autosomes during the course of evolution. According to the fish model system, this may have happened in several independent consecutive steps.
Key wordsChromosomal sex determination Heterochromatin “Junk” DNA DNA fingerprinting Oligonucleotide hydridization in situ
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- Beçak W (1983) Evolution and differentiation of sex chromosomes in lower vertebrates. In: Müller U, Franke WW (eds) Mechanism of gonadal differentiation in vertebrates. Differentiation [Suppl] 23:3–12Google Scholar
- Kallman KD (1984) A new look at sex determination in poeciliid fishes. In: Turner BJ (ed) Evolutionary genetics of fishes. Plenum Press, New York, pp 95–171Google Scholar
- Kirpichnikov VS (1981) Genetic bases of fish selection. Springer Verlag, BerlinGoogle Scholar
- Ohno S (1967) Sex chromosomes and sex linked genes. Springer Verlag, BerlinGoogle Scholar
- Ohno S (1972) So much “junk” in our genome. In: Smith HH (ed) Evolution of genetic systems. Gordon and Breach, New York, pp 366–370Google Scholar
- Ohno S (1974) Protochordata, cyclostomata and pisces. In: John B (ed) Animal cytogeneitcs, vol 4. Chordata 1. Bornträger, BerlinGoogle Scholar
- Schmid M (1983) Evolution of sex chromosomes and heterogametic systems in Amphibia. In: Müller U, Franke WW (eds) Mechanisms of gonadal differentiation in vertebrates. Differentiation [Suppl] 23:13–22Google Scholar
- Schröder JH (1983) The guppy (Poecilia reticulata Peters) as a model for evolutionary studies in genetics, behavior, and ecology. Beratungen Naturwiss-medizin Verein Innsbruck 70:249–279Google Scholar
- Winge O (1922) One-sided masculine and sex-linked inheritance inLebistes reticulatus. J Genet 12:145–162Google Scholar
- Winge O, Ditlevsen E (1947) Color inheritance and sex-determination inLebistes. Heredity 1:65–83Google Scholar