Authors: Mark Jones*
Chromatin is a complex of macromolecules made out of DNA, RNA, and protein, which is found inside the center of eukaryotic cells. Chromatin exists in two constructions: heterochromatin (united) and euchromatin (extended)... Read More»
Authors: A.C. Lira-Neto, G.M. Silva, R.C. Moura and M.J. Souza
Males of Zophobas aff. confusus and Nyctobates gigas (Tenebrionidae) collected in the State of Pernambuco, Brazil, were studied through conventional staining, C-banding, silver nitrate impregnation (AgNO3), and the base specific fluorochromes CMA3 and DAPI. Z. aff. confusus was found to have 2n = 20 (9+Xyp) while N. gigas exhibited 2n = 18 (8+neoXY). Larg.. Read More»
Authors: V.B. Bardella, A.L. Dias, L. Giuliano-Caetano, J.R.I. Ribeiro and R. Da Rosa
Belostoma, a genus of the family Belostomatidae, includes species of great ecological importance as biocontrol agents. Few species of these species have been the subject of cytogenetic analyses. Karyotypic evolution in this genus involves agmatoploidy and simploidy; there are also different sex chromosome systems. We examined two Belostoma species (B. dil.. Read More»
Authors: J.A. Bitencourt, P.R.A.M. Affonso, L. Giuliano-Caetano, P.L.S. Carneiro and A.L. Dias
Loricariidae (Siluriformes, Hypostominae) is one of the most diverse catfish families. In spite of the wide distribution of loricariids in South America, cytogenetic reports are available for only a few species, mostly from southern and southeastern Brazil. We made the first chromosomal analysis of Hypostomus aff. unae from th.. Read More»
Authors: E.S. Souza, K.C.C. Alevi, A.R. Ribeiro, M.B. Furtado, N.C.B.V. Atzingen, M.T.V. Azeredo-Oliveira and J.A. Rosa
Cavernicola pilosa is a triatomine species that lives in caves and feeds on bat blood. This vector has a wide geographical distribution, and is found in Brazil, Colombia, Panama, Peru, and Venezuela. Little is known about the reproductive biology of this species, because most previous studies have only characterized its morphology, morphometry, ecology, a.. Read More»
Authors: W. Staiber
In the chironomid Acricotopus lucidus, two cells with quite different chromosome complements arise from the last unequal spermatogonial mitosis, as a consequence of monopolar migration of the so-called germ line limited chromosomes (Ks). The cell receiving all the Ks, in addition to two sets of the regularly segregating somati.. Read More»
Authors: L.C. Rocha, G.A. Silva, F.O. Bustamante, R.A.D. Silveira,A. Mittlemann and V.H. Techio
Analyses carried out with fluorescence in situ hybridization (FISH) in C-metaphases of the Lolium-Festuca complex have shown the occurrence of spontaneous fragile sites (FSs) in 45S rDNA regions. FSs are expressed as gaps but they do not result in breaks or chromosomal fragments in these species. These gaps have high DNA conde.. Read More»
Authors: N.D. Betancourt-Mart�?nez, J. Jim�?©nez-Villarreal, P. Carranza-Rosales, N.E. Guzm�?¡n-Delgado, C. Leyva Orasma, E. Viveros Valdez and J. Mor�?¡n-Mart�?nez
Formaldehyde (FA) is an environmental xenobiotic, which is genotoxic and carcinogenic to humans and animals; it induces DNA damage, mutations, and clastogenicity during critical cytogenetic events. FA-mediated oxidative stress is an important mechanism that has been associated with the induction of cytotoxic and genotoxic damage. Therefore, the objective .. Read More»
Authors: A. Movafagh, S.A. Mortazavi-Tabatabaei and A.A. Kolahi
Heterochromatin is considered to play a role in protecting the genome against mutagens. Changes in the quantity and proportion of different types of satellite DNA could increase genetic susceptibility in individuals with heterochromatic variations; they cause chromosome instability and predispose patients to malignancies. We e.. Read More»
Authors: E.M. Abbas, A. Takayanagi, N. Shimizu and M. Kato
Myostatin is a negative regulator of the growth and development of skeletal muscle mass. In fish, myostatin is expressed in several organs in addition to skeletal muscle. To understand the mechanisms regulating myostatin gene expression in the sea perch, Lateolabrax japonicus, we examined the methylation status of the myostatin gene promoter region in sev.. Read More»