Karyotype Conservation in 2 Populations of the Parthenogenetic Scorpion Tityus serrulatus (Buthidae): rDNA and Its Associated Heterochromatin Are Concentrated on Only One Chromosome

Autor(es)

Schneider, Marielle C. ^[1] ; Cella, Doralice M. ^[2]

Afiliação do(s) autor(es)

^[1] Univ Fed Sao Paulo, Dept Ciencias Biol, BR-09972270 Sao Paulo - Brazil

^[2] Univ Estadual Paulista, Inst Biociencias, Dept Biol, Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: JOURNAL OF HEREDITY; v. 101, n. 4, p. 491-496, JUL-AUG 2010.
• Citações Web of Science: 16

Resumo

Within the order Scorpiones, the parthenogenetic mode of reproduction has been described for 11 species, 6 of which belong to the genus Tityus. In this work, an investigation of the chromosome characteristics of 2 populations of Tityus serrulatus, the first scorpion species known to be thelytokously parthenogenetic, is described. An analysis of 40 individuals revealed holocentric chromosomes of large, medium, and small sizes and an invariable diploid number of 2n = 12. In addition to the conserved macrokaryotype structure, specific chromosome regions also appeared unchanged within and between the samples studied; that is, each sample displayed only one chromosome carrier of the active nucleolar organizer region containing ribosomal genes (5.8S, 18S, and 28S) and AT-rich heterochromatin associated with the ribosomal DNA. The high conservation of the chromosomal features observed in T. serrulatus differed from that verified in certain species of other groups of animals that possess both holocentric chromosomes and parthenogenetic reproduction. Moreover, the cytogenetic results obtained herein permit us to suggest how the eggs of T. serrulatus develop, whether by apomixis or automixis. (AU)

• Processo FAPESP: 06/53275-3 - Diferenciação evolutiva entre os cromossomos holocêntricos e monocêntricos em algumas espécies de escorpiões da fauna brasileira, detectada pela análise ultraestrutural do complexo sinaptonêmico e regiões associadas, heterocromatina constitutiva e região organizadora de nucléolo
• Beneficiário: Marielle Cristina Schneider
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado