Currently a lecturer in Botany at Kasetsart University, Thailand, where I teach and study ecology and evolution of bryophytes and lichens.
A recent Ph.D. from the department of Integrative biology at University of California, Berkeley. My dissertation research focused on understanding adaptation and community assembly of a unique group of bryophytes that live primarily on the leaf surface (epiphyllous bryophytes).
Hybrids between the critically endangered Siamese crocodile (Crocodylus siamensis) and least-conc... more Hybrids between the critically endangered Siamese crocodile (Crocodylus siamensis) and least-concern saltwater crocodile (C. porosus) in captive populations represent a serious challenge for conservation and reintroduction programs due to the impact of anthropogenic activities. A previous study used microsatellite and mitochondrial DNA data to establish the criteria for identifying species and their hybrids; however, the results may have been influenced by biased allelic frequencies and genetic drift within the examined population. To overcome these limitations and identify the true signals of selection, alternative DNA markers and a diverse set of populations should be employed. Therefore, this study used DArT sequencing to identify genome-wide single nucleotide polymorphisms (SNPs) in both species and confirm the genetic scenario of the parental species and their hybrids. A population of saltwater crocodiles from Australia was used to compare the distribution of species-diagnostic...
Abstract Jade perch (Scortum barcoo) is a new teleost in the developing aquaculture freshwater fi... more Abstract Jade perch (Scortum barcoo) is a new teleost in the developing aquaculture freshwater finfish grow-out sector in Australia and China. However, key information on the breeding sex determination system (SDS) remains poorly understood, hampering sex control programs and genetic improvement. In this study, the jade perch SDS was examined by investigating genome-wide single-nucleotide polymorphisms (SNPs) using diversity arrays technology and cytogenetics analysis to identify the genomic variants associated with sex-linked regions. Although the cytogenetic results showed no variation in the chromosomal patterns between males and females, one male-specific locus and 13 male-linked loci were observed, suggesting that jade perch exhibits male heterogametic XX/XY SDS. Male-specific loci on the putative Y sex chromosome were also identified as an extremely small proportion of the genome. A homology search of the SNP loci revealed the male-specific loci were homologous to the Gypsy transposable element. This might be a remnant of an initial accumulation of repeats on the Y chromosome at the early stage of sex chromosome differentiation. The results provide a base for sex control breeding biotechnologies and genetic improvements to promote sexual size dimorphism and other new approaches to improve the commercial value of jade perch.
Hybrids between the critically endangered Siamese crocodile (Crocodylus siamensis) and least-conc... more Hybrids between the critically endangered Siamese crocodile (Crocodylus siamensis) and least-concern saltwater crocodile (C. porosus) in captive populations represent a serious challenge for conservation and reintroduction programs due to the impact of anthropogenic activities. A previous study used microsatellite and mitochondrial DNA data to establish the criteria for identifying species and their hybrids; however, the results may have been influenced by biased allelic frequencies and genetic drift within the examined population. To overcome these limitations and identify the true signals of selection, alternative DNA markers and a diverse set of populations should be employed. Therefore, this study used DArT sequencing to identify genome-wide single nucleotide polymorphisms (SNPs) in both species and confirm the genetic scenario of the parental species and their hybrids. A population of saltwater crocodiles from Australia was used to compare the distribution of species-diagnostic...
Abstract Jade perch (Scortum barcoo) is a new teleost in the developing aquaculture freshwater fi... more Abstract Jade perch (Scortum barcoo) is a new teleost in the developing aquaculture freshwater finfish grow-out sector in Australia and China. However, key information on the breeding sex determination system (SDS) remains poorly understood, hampering sex control programs and genetic improvement. In this study, the jade perch SDS was examined by investigating genome-wide single-nucleotide polymorphisms (SNPs) using diversity arrays technology and cytogenetics analysis to identify the genomic variants associated with sex-linked regions. Although the cytogenetic results showed no variation in the chromosomal patterns between males and females, one male-specific locus and 13 male-linked loci were observed, suggesting that jade perch exhibits male heterogametic XX/XY SDS. Male-specific loci on the putative Y sex chromosome were also identified as an extremely small proportion of the genome. A homology search of the SNP loci revealed the male-specific loci were homologous to the Gypsy transposable element. This might be a remnant of an initial accumulation of repeats on the Y chromosome at the early stage of sex chromosome differentiation. The results provide a base for sex control breeding biotechnologies and genetic improvements to promote sexual size dimorphism and other new approaches to improve the commercial value of jade perch.
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Papers by Ekaphan Kraichak