Acclimatization of transformed seaweed Kappaphycus alvarezii carrying lysozyme gene in culture flask and the cultivation in floating net cage in Pangkep coastal

The in vitro transformation of the lysozyme gene in seaweed K. alvarezii has been successfully executed to increase the viability against ice-ice disease. There were two major stages in this research; (1) transformation of lysozyme gene in seaweed K. alvarezii which was carried out on laboratory scale and the cultivation of gene-transformed explants in the culture flask stored in “culture chamber”; (2) the acclimatization in floating net cages of green nets (mesh size of 1 mm) with cage size of 50 x 50 x 50 cm, the population density of 200 explants and cultivated for two weeks. The explants were then transferred to blue nets (mesh size of 2 mm) with a cage size of 50 x 50 x 50 cm for four weeks of rearing. The plants were then enlarged using a long-line method in the floating net cage, by tying the seaweed using a double line with a gap of 15 cm each. The measurement of weight, bud lengths, and water quality was carried out within 2 weeks. The result shows that the daily growth rate of the transformed seaweed during the regeneration stage in the culture flask was around 0.33-0.4%/day, meanwhile during the acclimatization stage in the green nets the was 0.65-1.6%/day, and even more, increased during the acclimatization stage in the blue nets with DGR of 2.28-2.3%/day. During the enlargement stage in the floating net cages, the lysozyme-transformed seaweed showed an even higher DGR with a value of 3.2-8.2%/day. The results of the integration of the lysozyme gene in seaweed were indicated by the presence of a 670 bp of amplification products, that is the same total length of the 35 S-F promoter fragments and Nos T-R in the expression vector. Based on these results, the lysozyme gene was successfully transformed in K. alvarezii seaweed.

Transcriptome Atlas of 16 Donkey Tissues

Donkeys (Equus asinus) are important livestock with great economic value in meat, skin, and milk production. However, a lack of knowledge of the transcriptome landscape across a wide range of donkey tissues limits genetic selective breeding and conservation. Here we used transcriptomics to describe the transcriptome landscape, classify the tissue-specific gene expression across all primary donkey tissues, and present supplementary analyses on the protein level of additional donkey milk samples. Overall, 16,013 protein-coding genes and 21,983 transcripts were mapped to the reference genome, including 6,778 ubiquitously expressed genes and 2,601 tissue-enriched genes. Functional analysis revealed that the function of the tissue-enriched genes was highly tissue specific. Tissue-elevated genes that could be associated with unique phenotypes in donkey were analyzed. The results showed that, compared with those in human and other livestock, the lysozyme gene in donkey breast was specifically and highly expressed. The calcium-binding lysozyme, encoded by the lysozyme gene, was also detected in high amounts in donkey milk. Given those intact lysozyme genes that predict potentially functional calcium-binding lysozyme found in only a few species (e.g., donkey and horse), the high expression of the lysozyme gene in donkey breast may contribute to the high lysozyme content in donkey milk. Furthermore, 71% of the proteins in donkey milk overlapped with human milk protein, higher than the overlapping rates of bovine, sheep, and swine with humans. The donkey transcriptomic resource contributes to the available genomic resources to interpret the molecular mechanisms underlying phenotype traits.

Short Communication: Single nucleotide polymorphism in C-type lysozyme gene and its correlation with Aeromonas hydrophila resistance in African catfish Clarias gariepinus

Authors. 2020. Short Communication: Single nucleotide polymorphism in C-type lysozyme gene and its correlation with Aeromonas hydrophila resistance in African catfish Clarias gariepinus. Biodiversitas 21: 311-317. The chicken-type lysozyme (LYSC) gene has been demonstrated to play important roles in the fish protection system against bacterial infection. In this present study, we aimed to identify the single nucleotide polymorphism (SNP) within the LYSC gene of African catfish Clarias gariepinus and its possible association with Aeromonas hydrophila resistance, a major pathogenic bacterium in African catfish. The gDNA of the African catfish LYSC coding sequence was 1559 bp long, comprising of four exons and three introns. Six SNPs were identified in African catfish LYSC, namely SNP1-6. After the A. hydrophila challenge, we regarded the surviving individuals after the infection as the resistant group and the dead fish as the susceptible group. High-resolution melting (HRM) analysis on SNP2 revealed that the allele frequencies of TT, CC, and TC were of 27.78%, 5.55%, and 66.67% in the resistant group, while the frequencies of TT, CC, and TC were 16.67%, 27.78%, and 55.55% in the susceptible group, respectively. The expression of LYSC and other immune-genes in the resistant group was also higher in the liver, head kidney, and spleen. These results indicated that the LYSC gene might play an essential role in bacterial resistance, and the SNP2 within the LYSC gene may be associated with the resistance to A. hydrophila in African catfish.