Browsing by Author "Raghunandanan, K V"

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Chromosome architecture of desi pigs of Kerala
(Department of Animal Genetics and Breeding, College of Veterinary and Animal Sciences, Mannuthy, 2001) Jayan, K C; Raghunandanan, K V
A cytogenetic analysis of the chromosomes of black desi pigs of Kerala was carried out. Fifty four black desi pigs housed at the AICRP on pigs: centre for Pig Production and Research, Mannuthy formed the material for study. Forty five Large White Yorkshire pigs were also studied for comparison of the chromosome architecture. Metaphase spreads were obtained by peripheral blood leukocyte culture in RPMI 1640 medium. A combination of pokeweed nitrogen and phytohemagglutinin was used for initiating mitosis. The metaphase spreads were G-banded by incubating them in 2 x SSC containing trypsin solution for 45 minutes at 60°C. The number, morphology and morphometric measurements of chromosomes were studied. The distinct visible bands observed in G-banding was compared to that of the standard G-banded karyotype of pigs. The karyotype revealed in desi pigs a chromosome diploid number of 38 (2n = 19). This consist of six pairs of submetacentric chromosomes, four pairs of metacentric chromosomes, six pairs of acrocentric chromosomes and a pair of sex chromosomes, either XX or XY. The X-chromosome was submetacentric and Y-chromosome metacentric. In Large White Yorkshire pigs included in the present study also the diploid number of chromosomes is 38, with similar morphological characteristics for the chromosomes as that of the desi pigs. Thus in morphology and number of chromosomes, the desi pigs maintained a similarity to that of large White Yorkshire pigs. The relative length of the largest chromosome which was a submetacentric one in both breeds was 11.69 ± 0.19 in desi pigs and 11.35 ± 0.37 in large White Yorkshire pigs. The Y-chromosome was the smallest chromosome in desi and large White Yorkshire pigs. The Y-chromosome had a relative length of 1.95 ± 0.12 in desi pigs and 1.7 ± 0.07 in large White Yorkshire pigs. The relative length of X-chromosome of desi and large White Yorkshire pigs were 4.63 ± 0.25 and 5.01 ± 0.22 respectively. The arm ratio of the submetacentric chromosomes was highest for chromosome 2 in both the breeds. The arm ratio was lowest for chromosome 8 in desi pigs and chromosome 5 in large White Yorkshire pigs. The ann ratio of the X-chromosome was 1.97 ± 0.08 for desi pigs and 1.81 ± 0.15 for the large White Yorkshire pigs. The centromeric index measurements varied from 23.06 ± 0.84 to 42.68 ± 0.71 for desi pigs and 26.2 ± 0.89 to 39.45 ± 1.51 for large White , Yorkshire pigs. The centromeric index value was highest for chromosome 8 and lowest for chromosome 2 in both breeds. The X-chromosome had a Centromeric Index of 32.09 ± 1.17 in desi pigs and 36.33 ± 1.64 in large White Yorkshire pigs. The bands obtained by G-banding of the chromosomes of desi pigs were comparable to the standard G-banded karyotype of pigs.
Chromosome characterisation of malabari goats and its crosses in Kerala
(Department of Animal Breeding and Genetics, College of Veterinary and Animal Sciences, Mannuthy, 1992) Bindu, K A; Raghunandanan, K V
The chromosome profile of goats was studied with a view to find its number, to prepare the karyotypes of female and male goats of the Malabari and its crosses with Saanen and Alpine and to assess its morphometric values. The experiments were carried out in jugular blood lymphocytes. The cultures were prepared using RPMI 1640 as the medium. The comparative efficacy of different mitogens viz. PHA, PWM and their combination, with different incubation time, revealed that the combination of PHA and PWM at an incubation period of 70.5 h yielded the optimum results. The diploid number of chromosomes in all the genetic groups of goats were found to be 60. Autosomes as well as X chromosomes were found to be acrocentric. The X chromosome was quite prominent in being the longest of all. The Y chromosome was the shortest and the only metacentric in the complement. In karyotypes of the three genetic groups, it was observed that twenty-nine homologous pairs of autosome formed a closely graded seriation. Sexual dimorphism was exhibited with an unequal pair of X and Y chromosomes in males and an equal pair of X chromosomes in the females. The relative length was estimated for each pair of chromosomes in percentage. The X chromosome contributed to more than five per cent of the total complement length in all the three genetic groups. In Malabari, Saanen x Malabari and Alpine x Malabari, the relative length of the Y chromosomes were 1.552+0.10,1.321+0.09 and 1.548+0.10 respectively. The analysis of variance of relative length of X chromosomes revealed a significant difference among the three genetic groups.
Chromosome profile of cross-bred bulls in Kerala
(Department of Animal Breeding and Genetics, College of Veterinary and Animal Sciences, Mannuthy, 1994) Gopakumar, C P; Raghunandanan, K V
Cytogenetic study was conducted on 53 young cross-bred (Bos Taurus x B. indicus) bulls stationed at the farm at Dhoni, belonging to Kerala Livestock Development Board. Young bulls included those selected for superior semen quality and others just started producing semen. The bulls were classified into Jersey cross, Holstein-Friesian cross and Brown-Swiss cross based on the paternal line. The semen quality and related attributes of the bulls were recorded, and the association between these traits and the karyological parameters were determined. Comparative chromosome study were performed in the three genetic groups. Metaphase spreads for staining and G-banding were obtained by peripheral leucocyte culture technique. The basal medium used for culturing was RPMI 1640 and mitosis was initiated in lymphocytes by a combination of phytohemagglutinin and pokeweed mitogen. The G-banding was done by incubating the chromosome spreads in 2 x SSC containing trypsin solution for 45 minutes at 660C. Karyological parameters such as chromosome number, morphology, relative length, arm ratio and centromeric index were studied. The nature, number and position of G bands were also examined. The reproductive attributes recorded included age at first semen collection age at freezable semen production, volume of semen, sperm concentration, total sperm output in first ten collections, number of ejaculates accepted for freezing and total freezable sperm output in first ten collections, and the morphological abnormalities of sperms. All the bulls except one, exhibited a diploid chromosome complement (2n=60, XY) in their cells. There were 29 pairs of acrocentric autosomes and a sub-metacentric x chromosome. The Y chromosome was sub-metacentric in Holstein-Friesian cross, and apparently metacentric in other two genetic groups. In one bull diploid/tetraploid mosaicism was observed with 6.67 per cent of lymphocytes carrying 120 chromosomes. The mean relative length of longest and shortest autosomes were 6.0174 ± 0.0273 and 1.6186 ± 0.0101 respectively. The X and Y chromosomes had a mean relative length of 5.5918 ± 0.0401 and 1.9636 ± 0.0396 respectively. In the X chromosome the arm ratio was 2.47 ± 0.04 and the centromeric index was 28.74 ± 0.33. A total of 405 bands were identified in the karyotype of the bulls. The G-banding pattern of cross-bred bulls in Kerala was not previously investigated, and hence the banding pattern observed in the study would be useful for cytogenetic screening of bulls in the state. On Analysing the semen quality and related attributes of the bulls it was found that one of the bull was oligospermic. The semen of this bull exhibited a high frequency of loose sperm heads. Semen of another bull was found to contain abnormal percentage of sperms with persistant proximal cytoplasmic droplet. A third bull produced semen in which the frequency of sperms with knobbed acrosome defect was very high. All the three bulls had produced ejaculates which were found unsuitable for freezing. The incidence of diploid/tetraploid mosaicism was detected in the bull producing sperms with knobbed acrosome defect. None of the ejaculates of this bull was suitable for freezing. However, further study was essential to conclude on the association between mixoploidy and knobbed acrosome defect or its influence on semen freezability. The other two bulls with seminal abnormalities exhibited cytogenetic profile similar as that of bulls producing normal semen. The effect of genetic group on the morphometry of sex chromosomes was found to be insignificant. However, the Y chromosome morphology was observed to be a suitable marker for identifying Holstein-Friesian crosses among the cross-bred bulls used for breeding in Kerala.
Chromosome profile of zebu x taurus cattle in Kerala
(Department of Animal Breeding and Genetics, College of Veterinary and Animal Sciences, Mannuthy, 1988) Raghunandanan, K V; Mukundan, G
Delineation of random amplified polymorphic DNA markers in crossbred cattle
(Department of Animal Breeding and Genetics, College of Veterinary and Animal Sciences, Mannuthy, 2003) Anilkumar, K; Raghunandanan, K V
Evaluation of sister chromatid exchanges in cattle reared in a radio active belt area of Southern Kerala
(Department of Animal Breeding and Genetics, College of Veterinary and Animal Sciences, Mannuthy, 1999) Dinesh, C N; Raghunandanan, K V
A cytogenetic investigation on the effect of long-term. background radiation on cattle was carried out in this study. It involved the analysis of sister chromatid exchanges (SCEs) which was the most sensitive and quickest mammalian system to find out the effect of mutagens on genetic material. The technique standardized for sister chromatid differentiation (SCD) involved culturing of lymphocytes in RPMI-1640 medium and incorporation of 5-bromo-2-deoxy uridine (BrdU) at 20th hour of incubation. The cells were harvested at the end of 70th hour and the thionine stained~slides were exposed to UV light for one hour at a distance of one foot from the UV source. analysed for SCE. Metaphase spreads showing SCD were Cattle reared in the four coastal wards of Chavara Panchayat (Kovilthottam, Cherusseribhagam, Kolangarabhagam and Kari thura) were taken as experimental group. Cattle from University Livestock Farm (ULF) , Mannuthy, which has no reports of background radiation, formed the control group. The mean SCE frequency per cell was found to be 1.536 ± 0.249 and 3.368 ± 0.273 for control and experimental groups, respectively. The range and number of SCEs/cell/generation for control animals were 0 to 5 and 0.768, respectively. In the experimental group it was 0 to 9 and 1.684. Thus an increase of 119.27 per cent in SCE frequency was recorded in high background radiation area when compared to that of control. The mean SCE frequencies for cattle of Kovilthottam, Cherusseribhagam, Kolangarabhagam and Karithura were 4 ± 0.966, 2.563 ± 0.584, 3.206 ± .411 and 3.389 ± 0.504, respectively and the SCE ranges were 0 to 7, 0 to 6, 0 to 7 and 0 to 9. There was no significant difference in SCE frequency among the four wards. The difference between SCE frequencies of Kovilthottam, Kolangarabhagam and Karithura to that of control was significant. This could be due to the effect of high background radiation on DNA and chromosomes. However, difference in SCE frequency between Cherusseribhagam and control was not significant. This could be due to non- homogenous distribution of monazite deposits in the coastal belt. Though the increase in SCE frequencies in Karithura, Kolangarabhagam and Kovilthottam were statistically significant, cattle reared in this area did not reveal any deviation in physiological and phenotypic performance. Thus this study indicates that SCE frequenc,y for cattle reared in Chavara panchayat with high background radiation was significantly higher than that of control group. This discloses the occurrence of chromosomal damage in this area though these cattle performed normally. This may be because of the repair mechanism or balanced by exchange mechanism during active replication of chromosomes.
Marker assisted selection for milk production traits in vechur cattle
(Department of Animal Breeding and Genetics, College of Veterinary and Animal Sciences Mannuthy, 2005) Shymaja Uthaman; Raghunandanan, K V
Porcine immuno response as marker traits for selective breeding
(Department of Animal Genetics and Breeding, College of Veterinary and Animal Sciences, Mannuthy, 2002) Rajan, M R; Raghunandanan, K V
Survivability and better performance of pigs under tropical stress have been reported to be significantly influenced by immune responses. Immune response -traits under genetic control offer potential possibilities for exploited in commercial pig production. The present research project on the utilisation of porcine immune responses by estimating the magnitude of humoral and cell' mediated immune responses in Desi and Large White Yorkshire attempted to evaluate the genetics of immune responses and to identify the association between the immune response traits and economic traits. The immune response traits were studied in 150 piglets aged between two to three months, 75 each belonging to Desi and Large White Yorkshire of both sexes and sired by eight sires each. The immune response traits studied were antibody response to sheep red blood cells (SRBC), delayed type hypersensitivity (DTH) to intradermal injection of PHA-M and lymphocyte transformation response to BCG. The economic traits recorded were litter size at birth, litter weight at birth, litter size at weaning, litter weight at weaning, weaning mortality and the occurrence of diarrhoea and pneumonia. Naturally occurring antibodies to SRBC could not be detected in both the breeds. Peak antibody response to SRBC was obtained at day 7 post immunisation with a mean titre of 4.830. Heritability estimates of antibody response to SRBC were 0.8969 ± 0.4235, 0.9187 ± 0.4893 and 0.8174 ± 0.4893 respectively at 7th day, 15th day and 21st day post- immunisation. Litter size at birth and weaning had no significant influence on antibody response. Similarly, antibody response to SRBC among piglets was not influenced by the incidence of diarrhoea, pneumonia and pre-weaning mortality to a significant level. DTH responses to intradermal injection of PHA peaked at 24 hours post injection with a mean value of3.39 mm. The mean pre injection skin thickness was 3.508 mm and 3.012 mm among Large white Yorkshire and Desi pigs respectively. This difference was found to be significant (P<0.05) and this difference was due to the significant breed difference confounding with body weight classes. The effect of breed on PHA responses at 24, 48 and 72 hours were not significant. Sex of the pig also did not influence the PHA responses significantly. The body weight classes did not influence the DTH response to PHA significantly. Sire effect was not significant on the pre injection skin thickness. But the DTH response at 24 hours was influenced by the sires in both Large White Yorkshire and Desi pigs to a highly significant level (P