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Temperature tolerances (including lethal limits) and associated rates of thermal acclimation of fish are critical information in predicting fish responses to global climate changes. In this study, a partial sequence of the heat shock protein 70 gene (HSP70) from the fish species Channa striatus was isolated and characterized. Evolutionary process that led to the diversity of HSP70 specific to vertebrates was also analysed. Results revealed that HSP70 is highly homologous in other fish families. The conservation of the HSP 70 gene among fish families could be driven by forces of natural selection due to climatic change. We exposed C. striatus to heat shock (32 °C) and cold shock (16 °C) respectively, in order to examine the differences of temperatures in influencing the expression patterns of HSP70. We revealed that expression of HSP70 was higher at 32 °C than at 16 °C in most of the organs. Specifically, occurrence of chaperone activity of HSP70 was found at low temperature. Therefore, this fish was postulated that to seems to be able to survive at lower temperature compared to higher temperature indicating there is force of natural selection acting towards this HSP 70 gene. This will demonstrate the effect of global warming towards the fish survivability. more...

In this study we analyzed sequences of the COI gene to investigate the genetic structure and diversity in four populations of the Giant Malaysian Prawn, Macrobrachium rosenbergii, and to test the effectiveness of cyclical mating as means of securing genetic diversity. Forty-three haplotypes were generated for the parental populations; most of these were unique, with moderate genetic and low nucleotide diversities. However Tajima's neutrality test indicated a significant (p < 0.05) departure of the Negeri Sembilan population from the mutation–drift equilibrium, suggesting that it may be losing genetic variability. To combat this problem we recommend a seasonal fishing ban. The AMOVA test results (5.45%, p < 0.00001), the networking of haplotypes and their phylogenetic tree all revealed clear population structuring between the populations. Genetic or haplotype diversity in the progeny groups had increased indicating that a cyclical mating system could be an effective means of maintaining it. The utilization of unique haplotypes in aquaculture, developing DNA barcodes for broods in genetic improvement programs as well as in evaluating restocking activities is recommended. For a better insight into the differences between and among the populations, further investigations using nuclear markers are required. more...

Data collected on purebred Friesian Heifers imported from Netherlands were used in this research to estimate genetic and non-genetic parameters. The average age at first calving (AFC), gestation period (GP), number services per conception (S/C), calving interval (CI), total milk yield (TMY), daily milk yield (DMY) and lactation length (LL) ranges were 24.9±2.34 - 26.50±2.84 months, 274.21±55.57 - 273.3±4.03 days, 3.92±2.77 -2.3±1.7, 468.90±116.32 - 445.4±92.81 days, 5533.14±1546.03 - 3748.2±1095.2 kg, 15.10±3.58 - 11.00±2.42 kg, and 376.74±15.89 - 349.0±86 days respectively. Results showed that parity number had a significant (p < 0.05) effect on (S/C). Also age at first calving had a significant (p < 0.05) effect on milk yield per lactation and daily milk yield (p < 0.01). Year of calving presented a significant (p < 0.05) effect on DMY,S/C and (CI) (p < 0.001). Whereas place of birth had a highly significant effect (p < 0.001) on TMY and significant (p < 0.01) effect on AFC. Repeatability estimates for GP, S/C, CI, TMY, DMY and LL were found to be 0.170±0.045, 0.090±0.044, 0.361±0.047, 0.420±0.061 and 0.094±0.044, respectively. While heritability estimates by paternal half-sib method ranged from 0.003±0.078 for LL and 0.190±0.140 for AFC. Whereas, estimates calculated by daughter-dam regression were found to be 0.710±0.456, 0.320±0.168, 0.106±0.120, 0.100±0.150, 0.174±0.136 and 0,055±0.224 for AFC, GP, S/C, TMY, DMY and LL, respectively. Regarding phenotypic correlations among parameters, age at first calving was negatively correlated with other traits except for S/C and DMY. Whereas S/C exhibited positive phenotypic correlation with all the traits studied. Total milk yield was found to have positive correlation with DMY and LL. Concerning genetic correlations among traits were either inestimable or overestimated. more...