A rare chromosomal polymorphism in a Kangayam bull (Bos indicus) of south India

A chromosomal polymorphism was detected on karyological screening of Kangayam breeding sires prior to subjecting them for frozen semen collection. One bull possessed the chromosomal complement 2n = 60, consisting of 58 acrocentric autosomes, one large sub-metacentric X-chromosome, and one small acrocentric Y-chromosome with a small visible p-arm, which was further confirmed using CBG- and GTG-banding. This polymorphism was attributed to a heterochromatin variation of the acrocentric Y-chromosome routine in the Bos indicus Linnaeus, 1758 cattle.

Profiling of Chromosomal Complement in Nandidurga Goats of Karnataka

Background: To characterize the chromosomal complement of Nandidurga goats. Methods: Blood samples for short term lymphocyte culture were collected from 5 bucks and 5 does from its breeding tract and then mitotic chromosomal spreads were accomplished. Result: The diploid chromosome number was found to be 60, consisting of 58 acrocentric autosomes and 2 sex chromosomes (X and Y). The X chromosome was found to be the longest acrocentric and Y chromosome was found to be sub metacentric. The mean mitotic drive was 64.5±2.01 and 63.15±1.30 percent in bucks and does, respectively. The mean relative length of autosomes varied from 2.08±0.24 to 4.81±0.12 in does and 2.09±0.09 to 4.70±0.11in bucks. The relative length of X chromosome in does was 5.14±0.17 and that in bucks was 4.92±0.21, whereas Y chromosome had a relative length of 1.99±0.20. The mean Arms Ratio, Centromeric Index and Morphological Index were 2.47, 31.62 and 396.14, respectively. This cytogenetic analysis indicates the normal chromosomal complement in the studied Nandidurga goats.

Sex Differences in the Immune System Become Evident in the Perinatal Period in the Four Core Genotypes Mouse

We have used the four core genotypes (FCG) mouse model, which allows a distinction between effects of gonadal secretions and chromosomal complement, to determine when sex differences in the immune system first appear and what influences their development. Using splenic T cell number as a measure that could be applied to neonates with as yet immature immune responses, we found no differences among the four genotypes at postnatal day 1, but by day 7, clear sex differences were observed. These sex differences were unexpectedly independent of chromosomal complement and similar in degree to gonadectomized FCG adults: both neonatal and gonadectomized adult females (XX and XY) showed 2-fold the number of CD4+ and 7-fold the number of CD8+ T cells versus their male (XX and XY) counterparts. Appearance of this long-lived sex difference between days 1 and 7 suggested a role for the male-specific perinatal surge of testicular testosterone. Interference with the testosterone surge significantly de-masculinized the male CD4+, but not CD8+ splenic profile. Treatment of neonates demonstrated elevated testosterone limited mature cell egress from the thymus, whereas estradiol reduced splenic T cell seeding in females. Neonatal male splenic epithelium/stroma expressed aromatase mRNA, suggesting capacity for splenic conversion of perinatal testosterone into estradiol in males, which, similar to administration of estradiol in females, would result in reduced splenic T cell seeding. These sex steroid effects affected both CD4+ and CD8+ cells and yet interference with the testosterone surge only significantly de-masculinized the splenic content of CD4+ cells. For CD8+ cells, male cells in the thymus were also found to express one third the density of sphingosine-1-phosphate thymic egress receptors per cell compared to female, a male characteristic most likely an indirect result of Sry expression. Interestingly, the data also support a previously unrecognized role for non-gonadal estradiol in the promotion of intra-thymic cell proliferation in neonates of both sexes. Microarray analysis suggested the thymic epithelium/stroma as the source of this hormone. We conclude that some immune sex differences appear long before puberty and more than one mechanism contributes to differential numbers and distribution of T cells.

El cariotipo de Paspalum cromyorrhizon diploide y tetraploide (Poaceae, Panicoideae, Paspaleae)

Paspalum cromyorrhizon Trin. ex Döll is a species adapted to low and humid fields, river and stream banks, throughout S Brazil, Uruguay and NE Argentine. Diploids (2n = 2x = 20) and tetraploids (2n = 4x = 40) from natural populations of P. cromyorrhizon from Corrientes (Argentina) were used to analyse the karyotype morphometry of both cytotypes. The chromosome count was performed using classical Feulgen staining. The karyotype of diploid P. cromyorrhizon has 20 metacentric chromosomes, while the tetraploid has a karyotype of 40 metacentric chromosomes. The total length of the chromosomal complement in diploids is 32.5 μm and in tetraploids 63.5 μm, the total monoploid chromosome length is 15.48 μm in diploids and 15.21 μm in tetraploids and both karyotypes are symmetrical. Karyotype analysis confirms the autopolyploid origin proposed for tetraploids.

Karyomorphological study of Houttuynia cordata Thunb.: an ethnobotanical species of Manipuri community of Tripura, India

Houttuynia cordata Thunb. (Saururaceae), has the chromosome number of 2n = 112 with karyotype formula A2+B98+C12. The size of the chromosomal complement was found to range from 1.52 µm to 3.00 µm with one pair of chromosomes bearing secondary constrictions. The detailed karyotype analysis revealed that chromosomes fall under the Stebbins category of 1A, which indicating slightly asymmetric nature of chromosome. The chromosome tally and conformity of the karyotype in the present study corroborated as a new cytotype being adapted in this area, the north-eastern region of India.

Chromosomal complement and distribution of the social vole (Microtus socialis parvus Satunin, 1906) in the North Caucasus

In the article the chromosomal complement of the social vole (Microtus socialis parvus Satunin, 1906) from five additional points of the North Caucasus is studied in a comparative aspect. Much attention is given to the distribution of this species taking into account the landscape structure and biotopic allocation. It is concluded that the karyotype of the social vole in the analysed area is not susceptible to polymorphism. The chromosomal complement of all studied individuals is identical in the number and morphology of chromosomes.

Male sex chromosomal complement exacerbates the pathogenicity of Th17 cells in a chronic model of CNS autoimmunity

SummarySex differences in the incidence and severity of multiple sclerosis (MS) have long been recognized. However, the underlying cellular and molecular mechanisms for why male sex is associated with more aggressive and debilitating disease remain poorly defined. Using an T cell adoptive transfer model of chronic EAE, we find that male Th17 cells induced disease of increased severity relative to female Th17 cells, irrespective of whether transferred to male or female recipients. Throughout the disease course, a greater frequency of male Th17 cells produced the heterodox cytokine IFNγ, a hallmark of pathogenic Th17 responses. Intriguingly, sex chromosomal complement, and not hormones, were responsible for the increased pathogenicity of male Th17 cells and an X-linked immune regulator, Jarid1c, was downregulated in both pathogenic male Th17 and CD4+ T cells from men with MS. Together, our data indicate that male sex critical regulates Th17 cell plasticity and pathogenicity via sex chromosomal complement.