Assessment of adaptability of zebu cattle (Bos indicus) breeds in two different climatic conditions: using cytogenetic techniques on genome integrity.

The aim of this study was to evaluate the genome integrity so as to assess the adaptability of three breeds of indigenous cattle reared under arid and semi-arid regions of Rajasthan (Bikaner) and Haryana (Karnal) India. The cattle were of homogenous group (same age and sex) of indigenous breeds viz. Sahiwal, Tharparkar and Kankrej. A total of 100 animals were selected for this study from both climatic conditions. The sister chromatid exchanges (SCE's), chromosomal gaps and chromatid breaks were observed in metaphase plates of chromosome preparations obtained from in vitro culture of peripheral blood lymphocytes. The mean number of breaks and gaps in Sahiwal and Tharparkar of semi-arid zone were 8.56 ± 3.16, 6.4 ± 3.39 and 8.72 ± 2.04, 3.52 ± 6.29, respectively. Similarly, the mean number of breaks and gaps in Tharparkar and Kankrej cattle of arid zone were 5.26 ± 1.76, 2.74 ± 1.76 and 5.24 ± 1.84, 2.5 ± 1.26, respectively. The frequency of SCEs in chromosomes was found significantly higher (P < 0.05) in Tharparkar of semi-arid region (4.72 ± 1.55) compared to arid region (2.83 ± 1.01). Similarly, the frequency of SCEs was found to be 4.0 ± 1.41 in the Sahiwal of semi-arid region and 2.69 ± 1.12 in Kankrej of arid zone. Statistical analysis revealed significant differences (P < 0.05) amongst the different zones, i.e. arid and semi-arid, whereas no significant difference (P > 0.05) was observed in the same zone. The analysis of frequency of CAs and SCEs revealed significant effects of environmental conditions on the genome integrity of animals, thereby indicating an association with their adaptability.

Expression profiling of major heat shock protein genes during different seasons in cattle (Bos indicus) and buffalo (Bubalus bubalis) under tropical climatic condition.

Heat shock proteins consist of highly conserved stress proteins, expressed in response to stress and play crucial roles in environmental stress tolerance and adaptation. The present study was conducted to identify major types of genes under the HSP70 family and other HSPs and to evaluate their expression pattern in Sahiwal and Tharparkar breeds of zebu cattle (Bos indicus) and Murrah buffalo (Bubalus bubalis) with respect to different seasons. Quantitative real time polymerase chain reaction was performed to analyze the transcript variants of three HSP70 family genes (HSPA1A, HSPA1B, and HSPA8) and HSP10, HSP60, HSP90 and HSF1 in each breed. The major finding of this study was the higher abundance of all the studied HSP genes during summer and winter compared to spring season, but the magnitude of increase was higher during summer as compared to winter. HSPA1A and HSPA1B genes showed maximal induction (P<0.001) during summer and winter while HSP60 and HSP10 were found to be the second most abundantly expressed HSPs. The relative mRNA abundance of HSF1 significantly increased (P<0.001) in Murrah buffalo compared to Tharparkar and Sahiwal cattle during summer and winter. Expression pattern of heat shock protein genes indicated that amongst the breeds, the expression was higher in Murrah buffalo compared to Sahiwal and Tharparkar cattle, thereby indicating the more adaptive capacity of later during periods of stress. Hence, this study suggests that heat shock protein genes may be conveniently used as biomarkers for assessing stress response in cattle and buffalo and the expression is species and breed-specific. Furthermore, the variation in expression is associated with heat tolerance and adaptation to different climatic conditions.

Relationship of conventional and fluorescent microscopic technique to assess in vitro semen quality status of Murrah buffalo males.

In vitro fertility assessment using fluorescent technique is a better predictor of fertility status of bulls as compared to traditional semen quality assessment techniques, therefore, the study was planned to assess in vitro fertility status of bulls based on conventional and fluorescent techniques. Seventy-three ejaculates were collected from 12 Murrah buffalo bulls maintained at Artificial Breeding Research Centre, NDRI, Karnal, India for the experiment and subjected to statistical analysis using SYSTAT. The mean values of ejaculate volume (ml), mass activity, individual motility (%), sperm concentration (millions/ml), live sperm (%), total abnormalities (%), HOST (%) and acrosomal integrity (%) were 2.70 ± 0.28, 2.8 ± 0.14, 63.8 ± 2.16, 1749.7 ± 122.24, 77.3 ± 2.48, 6.2 ± 0.51, 75.1 ± 1.81 and 84.5 ± 2.26, respectively. The repeatability estimates were significant (P<0.05) for ejaculate volume (0.34 ± 0.137), acrosomal integrity (0.29 ± 0.134) and live percentage (0.28 ± 0.133), indicating sufficient bull to bull variation for the parameters. The mean values of seminal attributes of fluorescent based criteria of CMA3 (Chromomycin A3), SYBR-PI and FITC-PNA (fluorescent isothiocynate-conjugated peanut agglutinin) were 5.25 ± 0.41, 67.91 ± 1.24 and 82.00 ± 1.25 percent, respectively. Bulls were ranked on the basis of expected producing ability (EPA) for semen characteristics assessed by conventional and fluorescent criteria. Rank correlations were found to be significant for FITC with most of the parameters evaluated by conventional methods. In conclusion, among the conventional criteria, individual motility (%) revealed ranking of bulls almost similar to that of fluorescent criteria.

Genetic variations in immunoglobulin G3 and association with staphylococcal intra-mammary infections in cattle and buffaloes.

Animals (n = 152) suffering with mastitis were used to study association between immunoglobulin G3 (IgG3) genotypes and staphylococcal mastitis. Thus, animals (affected and unaffected) were evaluated using PCR-RFLP. Restriction digestion of amplicons of IgG3 using BstYI showed allele A and, genotypes AC, AB and AA predominated in Karan Fries, Sahiwal and Murrah, respectively. HphI digestion revealed allele A and, genotypes AC and AB in higher frequency in animals of first group of all the breeds. Additionally, genotypes associated with mastitic infection showed predominance of AB (BstYI) in unaffected animals of Sahiwal and Murrah; whereas AC and AA were observed in affected group only. Genotype AB (HphI) was prevalent in unaffected and AC in affected animals of Karan Fries and Sahiwal. In Murrah, AC was common in affected and unaffected animal; while AB remained in affected category. Identified genotypes associated with determinants of SpA gene of S. aureus strains revealed the significant outcome. For example AB (BstYI) was found to be correalted with SpA ≤ 7R; whereas with SpA > 7R in Karan Fries. Genotypes AA and AB were more favorably associated with SpA ≤ 7R and AB with the SpA > 7R in Sahiwal cattle. The genotype AB seemed influenced (100%) with SpA > 7R and AC in SpA ≤ 7R in cases of Murrah. Similarly, AA (HphI) in Karan Fries was more likely to be correlated with SpA ≤ 7R, while AC with SpA > 7R. Overall, the molecular analysis revealed that IgG3 gene could be use for selection of animals against mastitis. However, further investigations on IgG3 needed to aid in identify disease- resistant animal.

Incidence of staphylococci and streptococci during winter in mastitic milk of sahiwal cow and murrah buffaloes.

Mastitis is a serious problem in dairy sector and among various aetiological agents, the incidence of staphylococci and streptococci remains high in milking animal. The present study was focused on detection of staphylococci and streptococci in winter season. Milk samples (117) of mastitic animals were tested for presence of staphylococci and streptococci using biochemical and PCR based assays. The testing revealed majority of animals (90.6%) were infected with more than one causative agent. Amongst 117 sample, 109 and 90 comprised of staphylococci and 90 streptococci, respectively. Distribution proportion of S. aureus, S. epidermidis, S. agalactiae, S. uberis and S. dysgalactiae among the mastitic cases was found as 64.9, 7.7, 5.1, 1.7, 48.7, 65.8 and 0.8%, respectively. Streptococci and staphylococci were observed in different combinations and the frequent were S. aureus/S. agalactiae/S. uberis, S. aureus/S. uberis, S. aureus/S. agalactiae and S. agalactiae/S. uberis which were accounted for 23.9, 19.7, 5.9 and 2.6%, respectively. Approximately half of the (52.1%) cases were observed for reoccurrence of mastitis. Reoccurrence of mastitis in winter season among these cases was significantly low as compared to summer (cattle-5 cases; buffaloes-2 cases). In addition, prevalence of S. aureus, S. agalactiae, S. uberis, and S. epidermidis in reoccurring mastitic cases was 73.7, 63.9, 45.9 and 6.6%, respectively. The observations revealed mastitis causing pathogens remains in hidden phase in winter season; however, cannot be neglected. The observation might be helpful in culling or segregation of cows for mastitis reduction programmes.

Antibiotic resistance and pathogenicity factors in Staphylococcus aureus isolated from mastitic Sahiwal cattle.

Methicillin-resistant Staphylococcus aureus (MRSA) poses a serious problem in dairy animals suffering from mastitis. In the present study, the distribution of mastitic MRSA and antibiotic resistance was studied in 107 strains of S. aureus isolated from milk samples from 195 infected udders. The characterizations pathogenic factors (adhesin and toxin genes) and antibiotic susceptibility of isolates were carried out using gene amplification and disc diffusion assays, respectively. A high prevalence of MRSA was observed in the tested isolates (13.1%). The isolates were also highly resistant to antibiotics, i.e. 36.4% were resistant to streptomycin, 33.6% to oxytetracycline, 29.9% to gentamicin and 26.2% each to chloramphenicol, pristinomycin and ciprofloxacin. A significant variation in the expression of pathogenic factors (Ig, coa and clf) was observed in these isolates. The overall distribution of adhesin genes ebp, fib, bbp, fnbB, cap5, cap8, map and cna in the isolates was found to be 69.1, 67.2, 6.5, 20.5, 60.7, 26.1, 81.3 and 8.4%, respectively. The presence of fib, fnbB, bbp and map genes was considerably greater in MRSA than in methicillin-susceptible S. aureus (MSSA) isolates. The proportions of toxin genes, namely, hlb, seb, sec, sed, seg and sei, in the isolates were found to be 94.3, 0.9, 8.4, 0.9, 10.2 and 49.5%, respectively. The proportions of agr genes I, II, III and IV were found to be 39.2, 27.1, 21.5 and 12.1%, respectively. A few isolates showed similar antibiotic-resistance patterns, which could be due to identical strains or the dissemination of the same strains among animals. These findings can be utilized in mastitis treatment programmes and antimicrobials strategies in organized herd.

Molecular surveillance of putative virulence factors and antibiotic resistance in Staphylococcus aureus isolates recovered from intra-mammary infections of river buffaloes.

In dairy and healthcare surroundings, Staphylococcus aureus has been documented as a leading pathogen. Prevalence of drugs resistant strains in mastitic ruminants is another serious problem. To elucidate the antibiotic-resistant and virulence gene patterns, S. aureus isolates (111) were recovered from intra-mammary infections suffering buffaloes, and characterized using PCR and disk diffusion assays. The pathogenic factors were associated with antibiotic-resistant patterns and analyzed. Molecular and phenotypic characterization of tested isolates showed significantly resistance to tetracycline, macrolides, lincosamides and aminoglycosides. MecA gene was detected in 5.4% of isolates of S. aureus. The isolates showed variation in expression of pathogenic factors. Coagulase genotype VI showed high antibiotics susceptibility while patterns I, III, IV and V belonged to resistant category of tested bacterial population. The prevalence of other virulent genes namely, Ebp, Fib, FnbB, Bbp and Map were present significantly in highly pathogenic isolates. The isolates (41.4%) were found positive for super-antigen enterotoxins Sec, See, Seg and Sei genes only and predominated in methicillin-susceptible compared to resistant ones. The allelic variants of Agr-1 and 3 were considerably associated with coagulase genotypes and other virulence factors, while the enterotoxins were found considerably associated with Agr-1 and 2. Distribution of virulent genes between methicillin-susceptible and resistant isolates was uneven. The distribution of high pathogenic characteristic in antibiotic-susceptible isolates indicated that these were equally responsible in maintaining the intra-mammary infections in animals and cannot be overlooked. The surveillance of pathogenic and antibiotics resistance factors of isolates revealed that certain genetic elements were over producing (Ebp, Fib, FnbB, Bbp, Map, TetK, MsrB, AacA-D) in mastitic S. aureus isolates especially from clinical cases. This outcome or genetic frame of S. aureus isolates may be further use for culling or segregation of animals infected with harmful strains to reduce the dissemination of pathogenic microorganisms or containment of mastitis.

Genetic determinants of antibiotic resistance in Staphylococcus aureus isolates from milk of mastitic crossbred cattle.

Staphylococcus aureus is one of the major causes of mastitis in dairy animals and its resistance against multiple antimicrobials always remains crucial concern. Present investigation was carried out to detect the distribution of antibiotic-resistant genes of S. aureus isolates. Isolates (128) of S. aureus from mastitic milk were collected, tested for antibiotics with disc-diffusion method, and resistant genes mecA, linA, msrA msrB, vatA, vatB, vatC ermA, ermC tetK, tetM and aacA-D were detected by PCR. The phenotypic antibiotics resistance percent in S. aureus isolates was classified as tetracycline (36.7), gentamycin (30.5), streptomycin (26.6), kanamycin (25.8) and penicillin G (22.7). All the isolates were susceptible to vancomycin. Among isolates, 10.2% were observed as methicillin-resistant. The distribution of antibiotic-resistant genes was linA (51.6) followed by msrB (46.1), tetK + M (34.4), msrA and aacA-D (26.6%). Different antibiotic-resistant genes combinations (mecA/linA-2; mecA/aacA-D/tetK/linA/msrB-3; mecA/linA/msrA/msrB-3; aacA-D/linA/msrA/msrB-4; aacA-D/linA/msrB-7; linA/msrA/msrB-10; tetK/linA/msrA/msrB-11; aacA/tetK/linA/msrB-12 isolates) were observed. All the isolates lacked amplification of vatA, vatB, ermA and ermC genes. Molecular typing resulted genetic variation in protein A (6-12 repeats) and coagulase genes (A-E patterns) were observed. Coagulase A and D genotypes were more prevalent in antibiotic-resistant isolates, while E, B and C in susceptible ones. The significant observation was the prevalence of methicillin-resistant S. aureus, which were resistant to multiple antibiotics. Findings revealed the status of resistant isolates in herd that might be helpful in treatment, controlling of resistant strains and culling of cows for mastitis reduction.

Statistical approaches for hydrogeochemical characterization of groundwater in West Delhi, India.

Parametric statistical approaches, correlations and multiple linear regressions were used to develop models for the interpretation of hydrogeochemical parameters in the Western part of Delhi state, India. The hydrogeochemical parameters indicated that the groundwater quality is not safe for consumption. The water is moderately saline and the salinity level is increasing over time. There is also the problem of nitrate pollution. The correlation between electrical conductivity (EC) and other water quality parameters except potassium (K(+)), nitrate (NO(3)(-)) and bicarbonate (HCO(3)(-)) is significantly positive and Ca(++)+ Mg(++)/Na(+)+ K(+) is significantly negative. In predicting EC, the multiple R(2) values of 0.996 and 0.985 indicate that 99.6% and 98.5% variability in the observed EC could be ascribed to the combined effect of Na(+), HCO(3)(-), Cl(-), SO(4)(--), NO(3)(-) and Ca(++)+ Mg(++) for the year of 2005 and 2006 respectively. Out of 99.6% of the variability in EC in 2005, 51.2% was due to Cl(-) alone, and 8.5%, 12.5%, 6.1%, 14.7% and 6.7% were due to Na(+), HCO(3)(-), SO(4)(--), NO(3)(-) and Ca(++) + Mg(++). Similarly in 2006, out of 98.5% of the variability in EC, 48.5% was due to Cl(-) alone, and 10.4%, 12.7%, 5.3%, 17.2% and 4.4% were due to Na(+), HCO(3)(-), SO(4)(--), NO(3)(-) and Ca(++)+ Mg(++). The analysis shows that a good correlation exists between EC, Cl(-) and SO(4)(--) either individually or in combination with other ions and the multiple regression models can predict EC at 5% level of significance.

Genetic variation within and among three Indian breeds of goat using heterologous microsatellite markers.

The parameters of genetic variation, genetic distances and time of divergence in three Indian goat breeds were studied using 16 cattle microsatellite markers. The mean number of alleles and mean allele size (bp) per microsatellite marker in goats were 5.37 +/- 0.78 and 143.9 +/- 33.75 bp respectively. The average values of heterozygosity and polymorphism information content were 0.54 +/- 0.2 and 0.48 +/- 0.20, respectively. Five of the eight genetic distance methods were highly correlated, revealing a closer relationship between Jamnapari and Barbari goats. A phylogenetic tree constructed from inter-individual distances revealed that the individuals clustered according to the breed to which they belonged, and the Jamnapari and Barbari goats formed a cluster. The divergence times between Sirohi and Jamnapari, and Sirohi and Barbari were approximately 2000 years, while its value between Barbari and Jamnapari goats was approximately 1370 years.

Chromosome configuration during in vitro maturation of goat, sheep and buffalo oocytes.

The competence of meiotic chromosome configuration at the time of co-culture of oocytes with spermatozoa is an essential prerequisite for successful in vitro fertilization (IVF). Although this technology has been used in several livestock species, various intrinsic and extrinsic factors affecting the high repeatablity of IVF have yet to be understood. The present study was conducted to determine the appropriate time for coculture of oocytes and spermatozoa in order to optimize the fertilization rate in sheep, goats and buffalo. Oocytes were collected from the ovaries of slaughtered animals. The oocytes were divided into 10 groups and cultured for maturation in TCM-199 supplemented with estrous cow serum for different durations at 38.5 x 0.5/C in a CO(2) incubator. Sheep and goat oocytes were removed from culture medium after 0,6,12,22,24,26,28,30,32 and 36 and buffalo oocytes after 0,6,12,16,20,22,24,26,28, and 36 h. The oocytes were treated with hypotonic solution (0.75 M KCl) and fixed in Carony's fixative on glass slides. The fixed oocytes were stained with Giemsa solution, and the meiotic chromosomes were evaluated under a compound microscope at x 1000 magnification. Observations were recorded on a total of 1328 oocytes (sheep, 409; goat, 727 and buffalo, 192). The sequential configurations of diffused chromatin, pachytene, diplotene (along with nucleoli), diakinesis and metaphase II (MII) were analyzed at different durations of culture. Control oocytes (fixed at 0 h without incubation) were mostly at the pachytene stage, and as the duration of culture increased the instances of diplotene, diakinesis and finally MII increased. Oocytes at the MII stage of meiosis are known to be at the optimal stage of development for co-culture with spermatozoa and successful in vitro fertilization. On the basis of sequential configuration of chromosomes, it was found that the optimal duration of in vitro maturation of oocytes is 32, 30 and 24 h for sheep, goats and buffalo, respectively.

Application of the RB-FPG technique for distinguishing early and late replicating X chromosomes in farm animals.

The sex chromosomes of Murrah buffalo and Sahiwal cattle (females) were studied for R-banding patterns. A short term whole blood culture method was used for obtaining metaphase chromosomes. The R-banding method using 5-bromo-2'-deoxyuridine (BrdU), the fluorescent 33258 Hoechst stain followed by blue-black light exposure and Giemsa staining (RB-FPG) was applied to the chromosome preparations. The two X chromosomes in all the females were clearly distinguished. One of the chromosomes (early replicating) had alternative light and dark bands and the other X chromosome (late replicating) was either completely pale banded or had one or a few dark bands. The reason for this phenomenon could be BrdU incorporation in the late replicating X chromosome, which on exposure to blue light in the presence of 33258 Hoechst is destroyed and does not take the stain. Thus, one of the two X chromosomes shows differential staining behaviour.

Characterization of a translocation and its impact on fertility in the pig.

A chromosome anomaly originally detected in two intersex pigs and previously reported as a Robertsonian translocation was characterized, and its transmission pattern was assessed by analyzing the progeny and immediate relatives of a sow. Cytogenetic investigations on four phenotypically normal relatives of the intersexes, including a sow, showed that the rearrangement was a reciprocal translocation involving the X chromosome and an autosome. Giemsa-banding and reverse-banding techniques indicated that the break in the X chromosome may have occurred in the terminal segment of the short arm (Xp) and that in the autosome in the proximal segment of the acrocentric chromosome 14 (14q). Reverse-banding techniques also revealed that the normal X is the late-replicating X in female translocation carriers. Centromere banding revealed an intercalary band on the long arm of the submetacentric chromosome representing the altered X in translocation carriers. The translocation was designated as rcp (X;14) (p+;q-). Chromosome analysis on 45 of 72 live offspring of the carrier sow showed a 20:25 distribution of carriers to normal piglets, with a carrier to normal ratio of 5:13 among females and 15:12 among male piglets, indicating an overall reduction of females (18) compared with males (27). Male carriers from one litter at sexual maturity showed hypoplastic testes and no spermatozoa in their ejaculates or fluid aspirates from the cauda epididymis. Their seminiferous tubules were narrow, spermatogenesis was impaired, and pyknotic and giant nuclei were abundant in the germinal epithelium. Meiotic preparations showed no stage beyond pachytene, suggesting that the absence of spermatozoa in the ejaculates may be due to the arrest of cells at the pachytene stage.

Relationships between the completion of first cleavage and the chromosomal complement, sex, and developmental rates of bovine embryos generated in vitro.

One thousand eighty-four two-cell bovine embryos produced from 1,574 oocytes matured and fertilized in vitro were cultured as groups separated according to the time when they completed their first cleavage (24, 30, 40, 48, or 62 hr postinsemination; hpi). At 5 days after insemination, the proportions of each group that had progressed to the eight-cell stage or beyond were determined and the 350 that had done so were fixed and examined cytogenetically for cell number, chromosomal abnormalities, and sex. Embryos in the "early" cleaving (24 and 30 hpi) and "late" cleaving (40-62 hpi) groups were compared. Early cleaving embryos were more likely to have developed to the eight-cell stage or beyond (52.2% vs. 20%), contained more cells (22 vs. 17), and were more likely to be male (3.6:1 vs. 0.93:1). It is suggested that these phenotypic differences between the sexes begin before the embryonic genome is generally thought to become activated and are due either to differential processing of X- and Y-bearing sperm within the zygote or to very early differential expression of genes derived from X- and Y-bearing sperm.

Sex-related differences in developmental rates of bovine embryos produced and cultured in vitro.

The classical concept of sex determination in mammals is that a Y chromosomal gene controls the development of the indifferent gonad into a testis. Subsequent divergence of sexual phenotypes is secondary to this gonadal determination. The most likely candidate gene is SRY (sex-determining region Y) in humans, and Sry in mouse. However, several lines of evidence indicate that sexual dimorphism occurs even before the indifferent gonad appears. Here we present evidence that bovine male embryos generally develop to more advanced stages than do females during the first 8 days after insemination in vitro. Corresponding relationships between both cell numbers and mitotic indices and sex were also seen. Although it is not clear whether this phenomenon involves factors originating before or after fertilization, these findings suggest that sex-related gene expression affects the development of embryos soon after activation of the embryonic genome and well before gonadal differentiation.

Development and viability of bovine embryos derived from oocytes matured and fertilized in vitro and co-cultured with bovine oviducal epithelial cells.

A co-culture system using a suspension of detached bovine oviducal epithelial cells (BOEC) has been developed as an effective culture method for supporting the development of bovine embryos derived from oocytes matured and fertilized in vitro. Four commercially available culture media (Waymouth's, Ham's F-10, TCM 199 and Ménézo's B2) supplemented with 10% oestrous cow serum, and a modified Tyrode's medium (TALP) supplemented with 0.6% bovine serum albumin were used. Ménézo's B2 resulted in the highest percentages of total uncleaved presumptive zygotes, and of the cleaved zygotes that reached at least the morula stage (31-46% and 66-74%, respectively). The embryos produced in vitro in B2 with BOEC resembled embryos produced in vivo with regard to numbers of cells (averaging 45.4 in morulae, 101.5 in blastocysts, 174.7 in hatching blastocysts and 195.9 in hatched blastocysts), rate of development (hatching on Day 8-9 of culture in vitro), rate of hatching (66% of cleaved zygotes) and pregnancy rates (63%) resulting from the transcervical transfer of selected embryos.

The sex ratios of bovine embryos produced in vivo and in vitro.

The male:female ratio of developing bovine embryos produced and allowed to develop in vitro and in vivo was determined retrospectively from the cytogenetic analysis of 804 embyos. The overall male:female ratio of the 307 (38%) embryos that could be sexed was 162 (52.8%):145 (47.2%) and did not differ (P>0.05) from the expected 1:1 ratio. Among premorula stage embryos produced in vivo (n = 66) and in vitro (n = 30), the ratios were 1.2:1 and 0.76:1, respectively. Among morulae and blastocysts produced in vivo (n = 74), produced and cultured in vitro (n = 106, and produced in vitro and cultured in vivo (n = 31), the ratios were 1.11:1, 1.3:1 and 0.94:1, respectively, none of which differed significantly from 1:1. There was no difference (P>0.05) in the number of cells or mitotic index between male and female morulae and blastocyst, respectively.

Glucose and glutamine metabolism in pre-attachment cattle embryos in relation to sex and stage of development.

Individual Day-7 embryos (morulae to expanded blastocysts) were incubated with radiolabelled substrates and karyotyped to determine the sex. In Exp. 1, embryos were incubated for 3 h with D-[1-14C]glucose, as a measure of the activity of the pentose-phosphate pathway (PPP) and D-[5-3H]glucose, as a measure of total glucose metabolism. The labelled products 14CO2 and 3H2O were collected throughout the measurement period. Total glucose metabolism in male embryos was twice that in female embryos and increased between the morula and expanded-blastocyst stages. Relative to total glucose metabolism, PPP activity was four times greater in female than in male embryos. In Exp. 2, embryos were cultured with D-[1-14C]glucose, and L-[3,4-3H(N)]glutamine (a measure of Krebs cycle activity) in the presence of brilliant cresyl blue, a stimulator of the PPP. Glutamine metabolism increased from the morula to expanded-blastocyst stages. Relative to the metabolism of glutamine, the activity of the PPP was one-third greater in female than in male embryos.

Genetic diseases of sheep and goats.

Congenital malformations and inherited disorders constitute a substantial proportion of the afflictions seen in sheep and goats. Of these, malformations tend to be similar in both species, whereas the genetic diseases encountered to date, with the exception of a few, are different. Of the 28 genetic diseases of sheep and goats described in this review, 60% and 62.5%, respectively, are monogenic disorders. For a majority of the monogenic recessive disorders encountered in these species, the carrier state is not detectable at present, whereas in others, in which a biochemical lesion is known (dermatosparaxis, erythrocyte glutathione deficiency, globoid cell leukodystrophy and glycogen storage disease), the carrier state is detectable with the aid of enzyme and surface protein markers. The latter group and the dominant disorders (anury, cataract, glomerulonephritis, and lethal grey in sheep; gynecomastia and anotia-microtia complex in goats) are easy to eliminate through selective breeding. The polygenic disorders (entropion, epidermolysis bullosa, hereditary chondrodysplasia, and muscular dystrophy of sheep, and udder problems in goats) are more difficult to eradicate, because the mutant genes responsible for these traits generally do not declare themselves until inbreeding brings together a critical concentration to create a health crisis in some, whereas others, which are only short of a few of these mutant genes, might go totally unaffected and therefore undetected. Chromosome defects of the structural nature (translocations) seen in sheep and goats generally create meiotic disturbances, which in a majority of cases lead to subfertility, whereas sex chromosome aneuploids are generally sterile.(ABSTRACT TRUNCATED AT 250 WORDS)

Monosomy X and gonadal dysgenesis in a buffalo heifer (Bubalus bubalis).

Investigations on a 3-yr-old river buffalo heifer presenting anestrus revealed a chromosome make-up of 2n=49 in the lymphocyte cultures, compared with the 2n=50 characteristic of riverine buffalo. The missing chromosome was identified as one of the Xs by karyotypic analysis, and monosomy X was confirmed by C and G-banding techniques. Both ovaries of the heifer were underdeveloped, although the other components of the internal genitalia were normal. The phenotypic and karyotypic features confirmed this to be a case of ovarian dysgenesis with 49,XO karyotype similar to that of the Turner's syndrome in man and other mammals.