Sustainable utilization and development of animal genetic resources

Animal genetic resources for food and agriculture play a multi-functional role, especially in developing countries. They are not only a source of animal protein but serve many other purposes. The diversity of livestock breeds and species, and even populations, is the result of evolutionary process and the influence of man. Over the last decades, in the developed countries and in some developing countries, indigenous and local breeds have been either replaced or crossbred by specialized high yielding breeds. Indigenous/local breeds have a larger gene pool and are often more adapted to the local management systems and low quality feed, require low maintenance, and are less prone to diseases. The exotic commercial breeds, however, due to selective breeding and intensification of production systems, have narrowed genetic base and require high quality feed and management. Genetic diversity is crucial for animals to adapt to changing environmental conditions and market demands. It is also the base material for selection and improvement of livestock productivity. Genetic erosion is of global concern. Managing animal genetic resources is a challenge requiring strategic interventions as it affects the food security, trade and livelihood of farmers. The Global Plan of Action for Animal Genetic Resources was developed by FAO with four strategic priorities areas to facilitate this. This paper addresses the Strategic Priority Area 2 of this action plan – sustainable use and development. Requirements for sustainable utilization of indigenous breeds and development of breeding strategies for present and future benefits are discussed

Genetic characterisation of animal genetic resources for sustainable utilisation and development

Farm animal genetic resources are not only a source of food and animal protein, but also play a multi-functional role providing other commodities and services. The vast array of breeds and species found across the world is the outcome of the effects of the environment over thousands of years and human activities. Over the last decades, however, this diversity has become threatened. Indigenous and local breeds, which are often more adapted to the local environmental conditions and management systems, require low maintenance and are less prone to diseases, have been either replaced by imported high yielding breeds or have their gene pool introgressed with genes from these breeds. The exotic breeds, which have been subjected to high intensity selective breeding, tend to have narrowed genetic base. Genetic diversity is crucial for animals to adapt to changing environmental conditions and to survive in the face of disease outbreaks. It is also the resource for improvement of livestock productivity to meet current and future demands. The loss of genetic diversity among animal genetic resources has caused global concern as it affects food security, trade and livelihood of farmers. With the need to arrest further genetic erosion, the Global Plan of Action for Animal Genetic Resources was developed by the Food and Agriculture Organisation of the United Nations (FAO). The first of the four strategic priorities areas focuses on characterisation, inventory and monitoring of trends and associated risks. The animal genetic resources of Malaysia comprise of the indigenous breeds, the local breeds, locally developed synthetic and composite breeds, traditional populations, commercial breeds and lines, and the introduced breeds. The indigenous and local breeds have been neglected in favour of imported breeds or have been indiscriminately crossed with other breeds resulting in non-descript crosses. Except for the recently developed synthetic breeds, many synthetic breeds developed in the past can no longer be found or suffer from admixture with genes from other breeds. We are rapidly losing our animal genetic resources. In addition to this the genetic diversity within the existing populations is fast eroding as a result of mismanagement of breeding activities and failure to keep proper records. Conservation and sustainable utilisation and development of animal genetic resources is only possible through genetic characterisation to identify unique qualities and to detect threats of inbreeding and hybridisation. Genetic characterisation is the evaluation of variation at the chromosomal or DNA level. It requires the assessment of genetic variability within and among populations, lines, breeds and species using molecular markers and specific genes. It may be used to explain population dynamics and migration patterns, and to identify inbreeding and admixture within livestock populations. It provides valuable information required for developing breeding strategies and genetic conservation strategies Association analysis using DNA markers and candidate genes may pave the path for use of marker-assisted selection (MAS) through early and accurate identification of animals with high breeding values and unique qualities. There are limited scientific studies evaluating the production and reproductive performances and genetic variability of local animal genetic resources. It is pertinent that the genetic structure of local animal genetic resources be evaluated and regularly monitored. Only then can our indigenous breeds, the locally developed synthetic breeds and non-descript crosses, and the introduced breeds besustainably developed to further enhance the local livestock industry and ensure food security in the future

Analysis of genetic variation of inducible nitric oxide synthase and natural resistance-associated macrophage protein 1 loci in Malaysian native chickens

The genetic diversity of 100 Malaysian native chickens was investigated using polymerase chain reaction-restriction fragment polymorphism (PCR-RFLP) for two candidate genes: inducible nitric oxide synthase (INOS) and natural resistance-associated macrophage protein 1 (NRAMP1). The two genes were selected because of their important role in chicken's immune system. INOS and NRAMP1 PCR products were digested by AluI and SacI restriction enzymes, respectively. The restriction digests produced fragment sizes of 322 and 173 bp for INOS and 722 and 79 bp for NRAMP1 as one allele and an undigested PCR product as the other allele. Both loci were polymorph, however only INOS gene showed Hardy-Weinberg equilibrium. Average heterozygosity and the Shannon information index (I) was 0.43 and 0.62 for INOS and 0.48 and 0.68 for NRAMP1 genes, respectively. The observed polymorphism in this study shows the ability of these candidate genes in marker assisted selection and introgression programs to increase resistance to diseases in both Malaysian native and commercial chickens

Comparison of effect of sex hormone manipulation during neonatal period, on mRNA expression of Slc9a4, Nr3c2, Htr5b and Mas1 in hippocampus and frontal cortex of male and female rats.

It has long been known that spatial memory and the ability to navigate through space are sexually dimorphic traits among mammals, and numerous studies have shown that these traits can be altered by means of sex hormone manipulation. Hippocampus, the main organ involved in this kind of memory, has specific signature genes with high expression level compared to other regions of the brain. Based on their expression levels and the role that products of these genes can play in processes like signal transduction, mediation of hormone effects and long term potentiation, these genes can be considered as genes necessary for routine tasks of hippocampus. Male and female rat pups were injected with estradiol and testosterone respectively. at early stage of their lives to examine the effect of sex hormone manipulation on mRNA expression of Slc9a4, Nr3c2, Htr5b and Mas1 using comparative quantitative real-time polymerase chain reaction. The results showed that expressions of these genes are strongly influenced by sex hormones in both the frontal cortex and hippocampus, especially in male hippocampus, in which expression of all genes were up-regulated. Htr5b was the only gene that was affected only in the males. Expression of Mas1 was contrary to expectations, showed stronger changes in its expression in cortex than in hippocampus. Nr3c2 was down regulated in all samples but up regulated in male hippocampus, and Slc9a4 also showed a huge up-regulation in male hippocampus compared to other samples

Characterization of bovine calpastatin gene in Nelore cattle using polymerase chain reaction-restricted fragment length polymorphisms

Problem statement: In beef cattle production, of meat quality and carcass traits are important. Traditionally beef cattle breeding programs unfortunately are time consuming and also recording of carcass and growth traits need heavy cost, Approach: Marker Assisted Selection (MAS) should be utilized in beef herds, along with economically important phenotypic traits, for genetic progress to made with respect to improving the uniformity and consistency of beef. Blood samples were collected from 41 nelor cattle in Malaysia. Forward and reversed primers amplified a 1552 bp fragment from calpastatin gene. XmnI enzyme was used for restriction analysis of PCR products. Result: Overall, the frequency of alleles A and B in the studied breeds were estimated as 0.42 and 0.58, respectively. In this study we calculated genotype frequency AA, AB and BB 12.2, 58.53 and 29.27% respectively and also observed heterozygosity, expected heterozygosity and average value of heterozygosity were 0.58, 0.49 and 0.48 respectively. Highest frequency of allele was B (0.58) and lowest was A (0.42) This Nelor cattle population was in the Hardy-Weinberg equilibrium. Conclusion: Perhaps, this molecular genetic information helps breeders for designing the proper genetic selection program in the development direction of this breed

Development of simple sequence repeat (SSR) markers for oil palm and their application in genetic mapping and fingerprinting of tissue culture clones

This study describes the application of a simple and effective method to isolate SSR markers from oil palm genomic sequences. A total of 12 informative SSR markers are described. The SSR markers were found suitable for genome analysis and DNA fingerprinting of oil palm tissue culture clones. Eleven of the 12 SSR markers exhibited expected Mendelian segregation ratios when tested on a mapping population, indicating their suitability for genetic mapping studies. The markers identified in the species Elaeis oleifera also showed applicability in a second species, that is Elaeis guineensis. Apart from genetic mapping, the SSR markers also showed promise as molecular probes for DNA fingerprinting of oil palm tissue culture clones. The SSR markers can be used for clonal identification, monitoring line uniformity between and within clones and detecting culture mix-up

Molecular characterization of tropical sweet corn inbred lines using microsatellite markers

Genetic variability among 13 tropical sweet corn inbred lines derived from source populations originating from five tropical countries was investigated using 95 polymorphic microsatellite markers. It was found that 92.9% of total molecular variance was due to variations among the inbred lines. This was further supported by the presence of high values of DST, FST, GST and FIT, indicating high genetic variation among the inbred lines. The average number of alleles and effective number of alleles were both close to one allele per locus per inbred line. Departure from Hardy-Weinberg equilibrium was observed with a drastic reduction of the observed heterozygosity, resulting in a lower index of genotypic diversity than expected for each of the inbred lines. The inbred lines were further assigned into six main heterotic groups based on their molecular characteristics using Fitch-Margoliash algorithm. High genetic variations among the inbred lines indicates the presence of different heterotic groups, while low level of genetic variability within the inbred lines indicates that they met the assumption of homozygosity of their loci to enable further diallel crosses to be made for analysis of their combining ability. It is therefore expected that high heterosis in yield and its components could be obtained from crosses among those inbred lines belonging to different heterotic groups