Channel catfish (Ictalurus spp.) is an economically important species in freshwater aquaculture around the world and occupies a prominent position in the aquaculture industry of the United States. MicroRNAs (miRNAs) play important roles in the regulation of almost every biological process in eukaryotes; however, there is little information available concerning miRNAs in channel catfish. In this study, a small-RNA cDNA library was constructed from 10 tissues of channel catfish, and Solexa sequencing technology was used to perform high-throughput sequencing of the library. A total of 14,919,026 raw reads, representing 161,288 unique sequences, were obtained from the small-cDNA library. After comparing the small RNA sequences with the RFam database, 4,542,396 reads that represent 25,538 unique sequences were mapped to the genome sequence of zebrafish to perform distribution analysis and to screen for candidate miRNA genes. Subsequent bioinformatic analysis identified 237 conserved miRNAs and 45 novel miRNAs in the channel catfish. Stem-loop RT-PCR was applied to validate and profile the expression of the novel miRNAs in 10 tissues. Some novel miRNAs, such as ipu-miR-129b, ipu-miR-7562 and ipu-miR-7553, were expressed in all tissues examined. However, some novel miRNAs appear to be tissue specific. Ipu-miR-7575 is predominantly expressed in stomach. Ipu-miR-7147 and ipu-miR-203c are highly expressed in heart, but are relatively weakly expressed in other tissues. Based on sequence complementarity between miRNAs and mRNA targets, potential target sequences for the 45 novel miRNAs were identified by searching for antisense hits in the reference RNA sequences of the channel catfish. These potential target sequences are involved in immune regulation, transcriptional regulation, metabolism and many other biological functions. The discovery of miRNAs in the channel catfish genome by this study contributes to a better understanding of the role miRNAs play in regulating diverse biological processes in fish and vertebrates.

The complete mitochondrial genome of the Colletes gigas (Hymenoptera: Colletidae) is determined to be 15,885 bp in length, containing 37 typical animal mitochondrial genes: 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes and a major non-coding AT-rich region. All PCGs initiate with typical ATN codons and end with the complete termination codon TAA, except for the cob gene, which harbors the stop codon of TAG. Twenty-four intergenic spacers (614 bp in total) and 7 overlapping regions (37 bp in total) are dispersed throughout the whole genome. The non-coding AT-rich region is 539 bp long and contains a tandem repeat region, which has also been reported in other insects. This is the first completely sequenced mitochondrial genome of the family Colletidae.

The objective of this study was to investigate the effects of single nucleotide polymorphisms (SNPs) in nine candidate genes on meat quality traits in longissimus dorsi muscle of pigs. Each SNP allele's main effects were as follows: ADRB3 c. 1192G allele increased intramuscular fat (IMF; p<0.01) and yellowness (p<0.05). MC4R c. 745G allele increased body weight (p<0.05). LEPR c. 232T allele increased rib eye area and decreased tenderness (p<0.05). HSL c. 873G allele increased rib eye area and decreased IMF and backfat thickness (p<0.05). LPL c. 74T allele increased IMF, tenderness, and yellowness (p<0.05). MYF5 c. 1205A allele improved tenderness (p<0.05). H-FABP c. 1322T allele improved tenderness and yellowness (p<0.05). PPARγ c. 175G allele decreased water loss (p<0.05). The identified genetic markers might be useful for evaluation and utilization of meat quality related gene in the effort to improve porcine meat quality.