The chromosomes of the Murrah (River), Swamp (Malaysian kerbau), F1 hybrid (Murrah × Swamp) and first generation backcross (F1 hybrid female × Murrah male) buffaloes (Bubalus bubalis L.) were studied using Giemsa (G) and centromeric (C) banding techniques. The diploid chromosome number for the Murrah was 2n = 50, Swamp 2n = 48, F1 hybrid 2n = 49 and two backcross animals had 2n = 49 and 2n = 50, respectively. The largest two metacentric chromosomes of the Swamp resulted from a tandem fusion between the two chromosomes 4p and 9, respectively, of the Murrah karyotype. The F1 hybrid (2n = 49) and one of the backcrosses (2n = 49) had karyotypes intermediate to the Murrah and Swamp parents. The C banding patterns were useful in identifying the X and Y chromosomes of the buffalo and demonstrated that a major portion of the centromere region of chromosome 9 was not incorporated into chromosome 4 during the tandem fusion.

Several sperm motility parameters in semen prepared by the swim-up technique were compared with IVF rates in 84 patients. The patients were either on clomiphene + human menopausal gonadotrophin or follicle stimulating hormone + human menopausal gonadotrophin stimulation regimens. Motility ratings were assessed both manually according to World Health Organization guidelines as well as computer-automated semen analysis (Cellsoft, Cryoresources, USA). Motility ratings of 2 2 yielded significantly higher fertilization rates (78-82%) than ratings below 2 (20-23%) (p < 0.001) for patients on both regimens. Velocity (41, 55, 78 pmlsec) and mean amplitude of lateral head displacement (1.96, 3.29, 4.91 pm) correlated significantly with and between manual ratings of 1, 2, and 3, respectively (r -0.83; p < 0.01). No significant differences were observed in linearity and beatlcross frequency between the manual ratings, although beatlcross frequencies tended to reduce linearly with increases in intensity of motility. The velocity of sperm motility has a significant effect on fertilization rates, and cut-off points of 2 2 or 2 50 pmlsec predict the actual potential and likely success of in vitro fertilization. These criteria on the swim-up semen should be used in the selection of patients admitted to IVF programs, and they justify the necessity of research investigations to improve motility in those patients with sluggish motility.

Scrotal circumference (SC) and body weight (BW) measurements were obtained from 122 crossbred (SaanenxLoca; JumnaparixLocal) bucks, ranging in age from 3 to 28 months. Spermatogenesis and semeniferous tubule diameters were studied from testicular biopsies in 24 bucks. The results showed that SC increased curvilinearly and was significantly correlated with age (P<0.05). Scrotal circumference correlated more significantly with BW (P<0.001). Spermatogenesis was completed at 6-7 months with a sudden increase in tubular diameter at the same time. Since SC is an indirect measurement of testicular size, a marked increase in testicular size indicated the onset of active spermatogenesis and, hence, the possibility of using bucks for breeding at an earlier age than normally recommended. Further, SC norms obtained in this study may become useful in the evaluation of bucks for breeding soundness.

No abstract

No abstract

Microfertilization of human oocytes with spermatozoa from a man with immotile cilia syndrome is reported, confirming a preliminary investigation where a zona-free donor oocyte was fertilized with spermatozoa from the same patient. Oocytes from his spouse were obtained by laparoscopy after routine stimulation with clomiphene citrate, human menopausal and chorionic gonadotrophins, and were cultured for 4-6 h in Whittingham's T6 medium, supplemented with 10% of her serum. The spermatozoa were washed and processed in the same medium and capacitated for 6-8 h before micromanipulation. Three of five mature oocytes were fertilized by micro-injection of a single immotile spermatozoon into the perivitelline space. One oocyte produced a two-pronuclear ovum assessed 19 h after injection, while the other two produced 2-cell embryos with blastomeres of equal size, 22 h after injection. These embryos cleaved to 3-8-cell stages in culture before embryo replacement. No pregnancy resulted from embryo transfer. The results conclusively demonstrate that human oocytes can be fertilized successfully with immotile spermatozoa by micro-injection and the work has profound implications in the treatment of severe male infertility.

No abstract

Chromosome analysis on different breed types of water buffaloes (Bubalus bubalis) was undertaken to identify their karyotypes and to determine the pattern of chromosome segregation in crossbred water buffaloes. Altogether, 75 purebred and 198 crossbred buffaloes including 118 from Malaysia and 80 from the Philippines, were analyzed in this study. The diploid chromosome number of the swamp buffalo from both countries was 48 and that of the river buffalo was 50, while all F1 hybrids exhibited 49 chromosomes. The F2 hybrids consisted of three different karyotype categories (2n = 48, 2n = 49, and 2n = 50), whereas the backcrosses included two different karyotype categories each, with 2n = 48 and 2n = 49 in the three quarters swamp types and 2n = 49 and 2n = 50 in the three quarters river types. Chi-square tests on pooled data from Malaysia and the Philippines indicated that the distribution of different karyotype categories of F2 animals did not deviate significantly from the 1:2:1 ratio expected if only balanced gametes with 24 and 25 chromosomes were produced by the F1 hybrids. In the three quarters swamp and three quarters river types, the respective karyotypic categories were in ratios approximating 1:1. The distribution of chromosome categories among the F2 hybrids and backcrosses suggests that only genetically balanced gametes of the F1 hybrids are capable of producing viable F2 and backcross generations.