World Aquaculture Singapore 2022

November 29 - December 2, 2022

Singapore

WHOLE GENOME SEQUENCING AND DEVELOPMENT OF SNP MARKERS FOR ROHU CARP Labeo rohita (HAMILTON)

Daniel G. Peterson1, Mark A. Arick II1, Chuan-Yu Hsu1, Adam Thrash1, Emma Ruth Miller1, Attila Karsi1, Mark Lawrence1, John Benzie2, Matthew Hamilton2, Md. Akhtaruzzaman Khan3, Md. Samsul Alam3*

 

1Mississippi State University, USA; 2WorldFish Center, Penang, Malaysia, 3Bangladesh Agricultural University, Mymensingh

*Department of Fisheries Biology and Genetics, Bangladesh Agricultural University

Mymensingh 2202, Bangladesh

samsul.alam@bau.edu.bd

 



Aquaculture and fisheries have long been recognized as a means by which Bangladesh can help feed and increase the nutritional health and wellbeing of its people. Labeo rohita (rohu) is one of several carp species that account for much of the protein in the diets of Bangladeshis. To provide insight into genes that can be used to increase the efficiency of aquaculture of rohu, we sequenced the whole genome of Labeo rohita. Briefly, blood from a single male rohu was used to isolate DNA. The DNA was sequenced using Illumina and Oxford Nanopore Technologies (ONT) platforms. Contigs were assembled using the ONT reads, and the Illumina data was used to correct errors in the ONT contigs. Hi-C chromatin configuration sequencing was conducted to further assemble the contigs into scaffolds. Functional annotations were done with Uniport Swisprot and InterproScan. The rohu genome assembly indicated that the rohu genome size is about 939.5 Mb in length, a value less than half the reported size of the rohu genome as determined by Feulgen densitometry (1C = 1950 Mb). To explore this discrepancy, we performed our own flow cytometric determinations of rohu genome size and found our flow cytometry estimates to be close to our predicted genome size (1C = 968 Mb average for five male rohu). The current assembly of the rohu is composed of 6,175 scaffolds, L50 is 26, and N50 is 1.29 Mb. Functional annotations indicated there are 29,494 genes with 30,480 mRNAs predicted. The Illumina sequences from fish collected from three different river systems (Padma, Jamuna and Halda) had a mapping rate around 99% against the genome assembly. From this mapped data filtering to SNPs between known NsiI-MspI restriction sites, the number of predicted SNPs found to be 469,392. SNP analysis indicated that fish collected from the Padma and Jamuna are genetically closer compared to Halda fish. The productivity of species depends on two things, management and biological potential of the species. By completing a high quality whole genome sequencing and assembly and developing SNP markers, we have created an opportunity to improve the biological/genetic potential of rohu. For this, it is essential to utilize this information to develop improved rohu strain by marker assisted selection.