DOG1 immunohistochemical staining of testicular biopsies is a reliable tool for objective assessment of infertility.

Testicular biopsy may be a component of the work-up of male infertility. However, no reliable diagnostic tools are available for objective quantitative assessment of spermatogenic cells. It is well known that MAGE-A4 is selectively expressed in spermatogonia and our group has previously demonstrated that DOG1 differentially stains germ cells. Therefore, we performed DOG1 and a double stain cocktail (DOG1 and 57b murine monoclonal anti-MAGE-A4) immunohistochemical stains on 40 testicular infertility biopsies (10 each with active spermatogenesis, Sertoli cell-only, hypospermatogenesis, and maturation arrest), 25 benign seminiferous tubules from radical orchiectomies, and 5 spermatocytic tumors (ST). In biopsies/resections with active spermatogenesis, DOG1 stained spermatocytes and spermatids and was absent in spermatogonia, while MAGE-A4 stained spermatogonia and primary spermatocytes (weak). In hypospermatogenesis, DOG1 highlighted decreased spermatocytes/spermatids and MAGE-A4 highlighted decreased spermatogonia. DOG1 staining confirmed decreased to absent spermatocytes in maturation arrest and MAGE-A4 staining established the presence of preserved spermatogonia in all cases. All STs were negative for DOG1 and positive for MAGE-A4, while all Sertoli cell-only cases were negative for DOG1 and the double stain cocktail. In conclusion, we confirmed that DOG1 is expressed in spermatocytes and spermatids and MAGE-A4 highlights primarily spermatogonia. Usage of these stains facilitates confirmation of maturation arrest, assessment of the percentage of testis involvement in hypospermatogenesis and identification of mixed patterns. Finally, this study supports that the differentiation of STs is more closely related to spermatogonia than the more mature spermatocytes.

Fertility Assessment in Sorraia Stallions by Sperm-Fish and Fkbp6 Genotyping.

The Sorraia, a critically endangered indigenous Iberian horse breed, is characterized by low genetic variability, high rate of inbreeding, bad sperm quality and subfertility. Here, we studied 11 phenotypically normal but subfertile Sorraia stallions by karyotyping, sex chromosome sperm-FISH and molecular analysis of FKBP6 - a susceptibility locus for impaired acrosome reaction (IAR). The stallions had normal sperm concentration (>300 million cells/ml), but the numbers of progressively motile sperm (21%) and morphologically normal sperm (28%) were invariably low. All stallions had a normal 64,XY karyotype. The majority of sperm (89%) had normal haploid sex chromosome content, although 11% of sperm carried various sex chromosome aneuploidies. No correlation was found between the percentage of sperm sex chromosome abnormalities and inbreeding, sperm morphology or stallion age. Direct sequencing of FKBP6 exon 4 for SNPs g.11040315G>A and g.11040379C>A revealed that none of the stallions had the susceptibility genotype (A/A-A/A) for IAR. Instead, all animals had a G/G-A/A genotype - a testimony of low genetic variability. The findings ruled out chromosomal abnormalities and genetic predisposition for IAR as contributing factors for subfertility. However, low fertility of the Sorraia stallions could be partly attributed to relatively higher rate of sex chromosome aneuploidies in the sperm.

Assessment of antifertility activities of abamectin pesticide in male rats.

The effects of abamectin pesticide on fertility of adult male Sprague-Dawley rats were investigated. Adult male rats were exposed to tap water containing 0, 571, 857, or 1714 ppm abamectin for 6 weeks. Based on fluid consumption, animals received 0, 1.19, 1.87, and 2.13 mg/animal/day abamectin, respectively. Fertility was significantly reduced in male rats ingesting abamectin at all three doses in that the number of females impregnated by them was significantly reduced. The number of viable fetuses was significantly reduced in females mated with males that ingested abamectin at 1.87 or 2.13 mg/animal/day. Significant increases in the total number of resorptions and the number of females with resorptions were observed in females mated with the exposed males at all three concentrations. The body weight gain and water consumption were significantly lower in males that ingested 2.13 mg/animal/day abamectin. Likewise, ingestion of abamectin at all three concentrations caused a significant increase in the weight of testes. Epididymal and testicular sperm counts and daily sperm production were significantly decreased in exposed males. The serum level of testosterone was significantly reduced, whereas the serum level of follicle-stimulating hormone was significantly increased in males that ingested abamectin at a concentration of 2.13 mg/animal/day. Histological evaluation of the testes revealed several abnormalities including infiltration with congested blood vessels with marked hemorrhage and a significant accumulation of connective tissue surrounding the seminiferous tubules. These results strongly suggest the adverse effects of abamectin pesticide on male rat fertility.

Reciprocal translocations in pigs. Their detection and consequences on animal performance and economic losses.

In France, the national computerized program for sow herd management regularly delivers a listing of hypoprolific boars for which a cytogenetic evaluation is required, and participates in the differential diagnosis of the other causes of reduced prolificacy. Two reciprocal translocations, 4/14 and 7/15, reducing the prolificacy by about 45 percent have been discovered since 1979. A third one, leading to a prolificacy reduction of about 28 percent, is described in the present paper. The effects of translocation 4/14 were studied in an experimental herd, in which the ovulation rate did not seem to be modified and the early embryonic mortality accounted for the decrease in litter size. The growth rate at day 35 was higher in piglets carrying the chromosomal abnormality than in their normal littermates, i.e., 215 vs. 182 g per day (P less than 0.10). The economic consequences of using a boar carrying a translocation on a group of 21 sows were estimated by means of a simulation model "Porsim." When prolificacy decreased by five piglets per litter, the losses represented 157 piglets, i.e., about $4000. If, in addition to this, the percentage of non-returns into heat decreased by 35 percent, the losses then represented 248 piglets, i.e., $6000. Because of this important economic risk, it is suggested that measures be taken to detect defective animals and to prevent their use.

Recent developments in methods of mosquito control.

Since residual insecticide spraying in domiciles does not sufficiently control some species of anophelines to halt malaria transmission, alternate methods of control have been investigated. These include ultra-low-volume (ULV) sprays or aerosols, the release of sterile males to suppress or eradicate populations, and the use of diseases or parasites to interfere with transmission or to reduce populations of mosquitos. The ULV aerial sprays gave practical control of Anopheles albimanus in Haiti and interrupted malaria transmission. The release of sterile males almost eliminated an isolated population of A. albimanus in a small valley in El Salvador. Studies are in progress to evaluate the effect on field populations of anophelines of a protozoan disease and two nematode parasites.