Conserving - Exploring

The laboratory of animal cytogenetics and comparative genomics (ACCG) was established in 2009 to promote expertise in chromosome analysis, comparative genomics, and genetic diversity in animals. Our aim is to clarify genome and chromosome structures to better comprehend genetic diversity and evolutionary processes using both cytogenetic, molecular biology, and genomic techniques. Karyotype and genomic evolution identify the processes of evolutionary changes in vertebrates, and chromosome homologies between different species are deduced by comparative chromosome mapping using cDNA or BACs. These techniques are now assessed through global research collaboration to conduct cross-species chromosome mapping for map-poor species, define intra- and inter-chromosomal rearrangements, and indicate sex chromosome evolution. Organization of repetitive elements in vertebrate genomes involves isolating satellite DNAs that may act as substrates for homologous or non-homologous recombination in genome rearrangements. An effective approach using fosmid library is ongoing to discover stDNAs from an increasing number of lineages.  Single-nucleotide polymorphism (SNP), microsatellite, and mitochondrial DNA are used to clarify evolutionary steps and diversity in vertebrates and address the status of genetic relationships and identification in terms of phylogenetics and barcodes. The lab housing KURDI-funded Kasetsart University Research and Development Institute, Center of Excellence on Agricultural Biotechnology: (AG-BIO/PERDO-CHE), the Center for Advanced Studies in Tropical Natural Resources, National Research University-Kasetsart University (CASTNAR, NRU-KU), the National Research Council of Thailand (NRCT), the Conservation Research and Education Division, Zoological Park Organization of Thailand, Thailand Research Fund (TRF), National Science and Technology Development Agency (NSTDA), and National Primate Research Center, Chulalongkorn University, Thailand provides cytogenetic resources and training for the scientific community in cytogenetics, genomics, and diversity. Our research goals are driven by the need to ensure an efficient and sustainable supply of medicine, food, and natural resources by addressing this major global challenge.

The aim of my study is to clarify genome and chromosome structures as well as their evolutionary processes in vertebrates by cytogenetic and molecular biology techniques. I plan to carry out the following research topics:

1. Karyological characterization in vertebrates
   To reveal the karyological characterization in vertebrates, the karyotyping, chromosome banding and FISH mapping are performed. The karyological characterization data would inform us the phylogenetic hierarchy of genome evolution in vertebrates and efficiently sustain the favorable selection in animal breeding program.

2. Karyotypic and genomic evolution in vertebrates
   To elucidate the process of karyotypic evolution in vertebrates, the chromosome homologies between different species in fish, amphibians, reptiles, birds and mammals are deduced using comparative chromosome mapping.

3. Origin and differentiation of sex chromosomes, diversity of sex-determining systems and sex-determining gene evolution in vertebrates
   Mammals and birds have a male heterogametic XX/XY-type sex chromosome, and a female heterogametic ZZ/ZW-type sex chromosome, respectively, whereas amphibians have both XX/XY- and ZZ/ZW-type sex chromosome. By contrast, XX/XY- and ZZ/ZW-type sex chromosome not only co-exist in reptiles and fish as genetic sex determination, but the environmental sex determination such as temperature is also found in both vertebrate groups. To clarify the origin and differentiation of sex chromosomes, the comparative chromosome maps of sex chromosomes are constructed and compared them with other species. Furthermore, sex-determining genes such as DM and SOX family are proposed to be a candidate gene of sex determination in vertebrates. The orthologues and paralogues of sex-determining gene, therefore, are studied to disclose gene evolution in vertebrate.

4. Organization of repetitive element in vertebrate genome
   Repetitive DNA sequences is a good chromosome marker for investigating the process of karyotypic evolution and sex chromosome identification, and for comparing the genomics structure of vertebrate species. This can be also a source for homologous recombination to initiate various categories of chromosomal rearrangements. Here, the characterization and comparison of organized repetitive element among different species should be conducted to find the common and specific repeats in the evolutionary line.

5. Mitochondrial genome analysis & DNA barcoding
   To clarify the step of evolution in vertebrates, complete mitochondrial genome analysis is used. The structure and organization are compared among different species within the same class. The complete mitochondrial sequence data sets are also scrutinized through cladistic analysis to demonstrate the genetic relationships among them. Furthermore, the sequence of mitochondrial genome is capable to develop molecular barcoding for identifying species.