title: A novel family of repetitive DNA sequences amplified site-specifically on the W chromosomes in Neognathous birds.
abstract: A novel family of repetitive DNA sequences was molecularly cloned from ApaI-digested genomic DNA of two Galliformes species, Japanese quail (Coturnix japonica) and guinea fowl (Numida meleagris), and characterized by chromosome in-situ hybridization and filter hybridization. Both the repeated sequence elements produced intensely painted signals on the W chromosomes, whereas they weakly hybridized to whole chromosomal regions as interspersed-type repetitive sequences. The repeated elements of the two species had high similarity of nucleotide sequences, and cross-hybridized to chromosomes of two other Galliformes species, chicken (Gallus gallus) and blue-breasted quail (Coturnix chinensis). The nucleotide sequences were conserved in three other orders of Neognathous birds, the Strigiformes, Gruiformes and Falconiformes, but not in Palaeognathous birds, the Struthioniformes and Tinamiformes, indicating that the repeated sequence elements were amplified on the W chromosomes in the lineage of Neognathous birds after the common ancestor diverged into the Palaeognathae and Neognathae. They are components of the W heterochromatin in Neognathous birds, and a good molecular cytogenetic marker for estimating the phylogenetic relationships and for clarifying the origin of the sex chromosome heterochromatin and the process of sex chromosome differentiation in birds.
authors.affiliation: Laboratory of Animal Cytogenetics, Division of Genome Dynamics, Creative Research Initiative Sousei, Hokkaido University, North 10 West 8, Kita-ku, Sapporo 060-0810, Japan.
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Yamada
authors.forename: Chizuko
authors.initials: C
authors.lastname: Nishida-Umehara
authors.forename: Junko
authors.initials: J
authors.lastname: Ishijima
authors.forename: Takahiro
authors.initials: T
authors.lastname: Murakami
authors.forename: Mami
authors.initials: M
authors.lastname: Shibusawa
authors.forename: Kimiyuki
authors.initials: K
authors.lastname: Tsuchiya
authors.forename: Masaoki
authors.initials: M
authors.lastname: Tsudzuki
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Matsuda
mesh_terms: D000818:Animals; D001483:Base Sequence; D002645:Chickens / Q000235:genetics; D002875:Chromosomes; D017124:Conserved Sequence; D003370:Coturnix / Q000235:genetics*; D004247:DNA / Q000737:chemistry*; D005260:Female; D046094:Galliformes / Q000235:genetics*; D006570:Heterochromatin; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D008969:Molecular Sequence Data; D012091:Repetitive Sequences, Nucleic Acid; D013045:Species Specificity
chemical_list: D006570:Heterochromatin; D004247:DNA