Differential sense and antisense expression profiles of Syrista parreyssi (Hymenoptera: Cephidae) mitochondrial transcripts

The transcription of the mitogenome shows a unique pattern that is both similar to and different from the nuclear and bacterial patterns. Mitochondrial transcription generates five polycistronic units from three promoters in Drosophila melanogaster, and different expression levels of genes were observed in both different and, interestingly, the same polycistronic units in D. melanogaster. This study was conducted to test this phenomenon in the mitogenome of Syrista parreyssi (Hymenoptera: Cephidae). RNA isolation and DNase digestion were performed using only one whole individual, and real-time polymerase chain reaction analyses were performed with complementary DNAs of 11 gene regions using gene-specific primers. It was found that the expression level of each gene exhibited differences from each other, and some genes (e.g., cox genes, and rrnS) were interestingly expressed at significant levels in the corresponding antisense chain. Additionally, the mitogenome of S. parreyssi was found to have the capacity to encode 169 additional peptides from 13 known protein-coding genes, most of which were encoded in antisense transcript units. One of the unique findings was a potential open reading frame sequence that was potentially encoded in the antisense rrnL gene and included a conserved cox3 domain.

A novel, conserved and possibly functional motif "WHWGHTW" in mitochondrial transcription across Bilateria

The animal mitogenomes which undergone a reductive evolution has an obvious loss of coding capacity compared to their known closest relatives, but it has not yet been fully investigated why and how the intergenic regions do not encode protein and have no known functions, are stably maintained, replicated, and transmitted by the genome. These relatively small intergenic regions may not be under neutral evolution and they may have functional and/or regulatory roles that have yet to be identified. Here, the distribution pattern, sequence content and location of a novel sequence motif of 'WWWGHTW' were bioinformatically investigated and characterised by constructing a sampling mitogenome dataset of 1889 species from 14 phyla representing the clade of Bilateria. This motif is reverse complementary of the previously described DmTTF binding sequence and found in the nd4L- (X) -trnT gene cluster. This cluster commonly exhibits a strand displacement region and an intergenic region among the bilaterian superphylums, particularly in Ecdysozoa. This motif may be accepted as a substrate providing binding sites for the specific interaction with transcription factors because of (i) its reverse complementarity of previously described DmTTF binding sequence, and (ii) the possession of G and T nucleotides in the fourth and sixth positions, (iii) the bias on T and G nucleotides instead of C and A in the degenerated positions. This suggestion is also supported by the presence of a strand displacement region in the nd4L- (X) -trnT gene cluster, particularly in Ecdysozoa consisting of the most rearranged mitogenomes among the bilaterian superphylums.

Computationally predicted SARS-COV-2 encoded microRNAs target NFKB, JAK/STAT and TGFB signaling pathways

Recently an outbreak that emerged in Wuhan, China in December 2019, spread to the whole world in a short time and killed >1,410,000 people. It was determined that a new type of beta coronavirus called severe acute respiratory disease coronavirus type 2 (SARS-CoV-2) was causative agent of this outbreak and the disease caused by the virus was named as coronavirus disease 19 (COVID19). Despite the information obtained from the viral genome structure, many aspects of the virus-host interactions during infection is still unknown. In this study we aimed to identify SARS-CoV-2 encoded microRNAs and their cellular targets. We applied a computational method to predict miRNAs encoded by SARS-CoV-2 along with their putative targets in humans. Targets of predicted miRNAs were clustered into groups based on their biological processes, molecular function, and cellular compartments using GO and PANTHER. By using KEGG pathway enrichment analysis top pathways were identified. Finally, we have constructed an integrative pathway network analysis with target genes. We identified 40 SARS-CoV-2 miRNAs and their regulated targets. Our analysis showed that targeted genes including NFKB1, NFKBIE, JAK1-2, STAT3-4, STAT5B, STAT6, SOCS1-6, IL2, IL8, IL10, IL17, TGFBR1-2, SMAD2-4, HDAC1-6 and JARID1A-C, JARID2 play important roles in NFKB, JAK/STAT and TGFB signaling pathways as well as cells' epigenetic regulation pathways. Our results may help to understand virus-host interaction and the role of viral miRNAs during SARS-CoV-2 infection. As there is no current drug and effective treatment available for COVID19, it may also help to develop new treatment strategies.

The regulation of trophoblast invasion and decidual reaction by matrix metalloproteinase-2, metalloproteinase-7, and metalloproteinase-9 expressions in the rat endometrium

PURPOSE

We aimed to evaluate how matrix metalloproteinases (MMPs) regulate the trophoblast invasion and placentation.

METHODS

Female rats were divided into the estrous cycle and early pregnancy day groups. Obtained uterine tissues and implantation sites were processed for immunofluorescence and real-time PCR examinations.

RESULTS

The mRNA expression of MMP-7 was higher than MMP-2 and MMP-9. Immunofluorescence findings confirmed that MMP-2, MMP-7, and MMP-9 were localized in the endometrial stroma, while MMP-7 was high in glandular and lining epithelial cells throughout the entire estrous cycle. However, their immunolocalizations and mRNA expressions were dramatically changed with the early pregnancy days. The MMP-7 reached very strong immunostaining in the giant trophoblast cells (GTCs), and the cytoplasm of mature and differentiating decidual cells, whereas MMP-2 and MMP-9 were mostly seen in the primary decidual zone (PDZ), GTCs, and the endothelium of blood vessels.

CONCLUSIONS

All three MMPs seemed likely to be a key mediator of trophoblast invasion into the decidual region as well as angiogenesis during the placentation process. Due to the strong and wide expression of MMP-7 in the mature decidua, it could be suggested that MMP-7 is important for decidual ECM remodeling and it might be used as a new marker of decidual reaction.

The first mitogenomes of the superfamily Pamphilioidea (Hymenoptera: Symphyta): Mitogenome architecture and phylogenetic inference

The Pamphilioidea represents a small superfamily of the phytophagous suborder Symphyta (Hymenoptera). Here, nearly complete mitochondrial genomes (mitogenomes) of three pamphilioid species: Chinolyda flagellicornis (Pamphiliidae), Megalodontes spiraeae and M. cephalotes (Megalodontesidae) were newly sequenced using next generation sequencing and comparatively analysed with the previously reported symphytan mitogenomes. A positive AT skew (0.013) and a negative GC skew (-0.194) were found in pamphilioid mitogenome, and a deviation from strand asymmetry was also observed in the PCGs encoded on both strands. Several gene rearrangement events were observed in four tRNA gene clusters (WCY, IQM, ARNS1EF and TP clusters), which have not been reported from symphytan mitogenomes to date. As the most parsimonious explanation, compared with the inferred insect ancestral mitogenome architecture, the occurrence of gene rearrangements in pamphilioid mitogenomes requires totally five evolutionary steps, including four transpositions and one inversion. The predicted secondary structures of tRNAs, rrnS and rrnL genes are mostly consistent with reported hymenopteran species. Phylogenetic analyses recovered the monophyly of superfamily Pamphilioidea and indicated the relationship Tenthredinoidea + (Pamphilioidea + (Cephoidea + (Orussoidea + Apocrita))) with strong nodal supports.