How do mammals count their X chromosomes and keep only one X active per cell? In this issue, Jonkers et al. (2009) show that Rnf12/RLIM, encoded by the X-linked gene Rnf12, induces X chromosome inactivation only when present above a certain threshold, a condition fulfilled when at least two Xs are active.

the chromosomal spread and karyotype of bleak (alburnus alburnus) from anzali lagoon were identified using tissue squashing techniques with injection of 0.5ml/100g body weight of 0.01% colchicines solution in fish fingerlings. kidney and gill tissues were then extracted and chopped in kcl 0.045m for 20 min and fixed in carnoy solution in 3 stages. the chromosomal spreads were stained in 20% gim...

Chromosome count is the only direct way to determine number of chromosomes a species. This study often considered trivial that seldom described and discussed in detail. Therefore, it inevitable chromosome protocol should be revised revisited before becomes obliterated. In present study, we encountered challenges obtaining clear micrograph for active mitotic cells Neolamarckia cadamba (Roxb.) Bo...

the biogeography of genus linaria was revealed by the available chromosome counts from all over the world. chromosome numbers of 92 taxa of the genus linaria are included in an on-line karyological database. furthermore, information about chromosome numbers taken from 374 literature sources was used in this paper. each database record includes name of taxon, data on chromosome and data on the o...

Chromosome numbers of one species Eranthemum (E. macrophyllum Wall. ex Nees) and five Strobilanthes [S. affinis (Griff.) Terao J. R. I. Wood et Benett., S. biocullata Y. F. Deng & Wood, dimorphotricha Hance, heteroclita D. Fang H. Lo pseudocollina K. He Qin] in the family Acanthaceae from China have been reported for first time. The chromosome were determined as 2n=4x=44 E. macrophyllum, 2n=2x=...

Phylogenetic analysis of amplified fragment length polymorphisms (AFLP) was used to infer patterns of morphologic and chromosomal evolution in an eastern North American group of sedges (ENA clade I of Carex sect. Ovales). Distance analyses of AFLP data recover a tree that is topologically congruent with previous phylogenetic estimates based on nuclear ribosomal DNA (nrDNA) sequences and provide...