Constitutively expressed MHC class Ib molecules regulate macrophage M2b polarization and sepsis severity in irradiated mice.

Macrophages can change their physiology in response to microenvironmental signals. This differentiation into classically activated M1 or alternatively activated M2 macrophages is known as polarization. In this study, we isolated bone marrow-derived macrophages from ß2m-deficient (deficient in both MHC class Ia and Ib) and Kb Db -deficient (deficient only in MHC class Ia) mice and found that ß2m-deficient macrophages showed a significantly lower M2b polarization efficiency. In addition, the absence of constitutive MHC class Ib expression decreased the stability of the Notch-1 intracellular domain. Finally, we found that ß2m-deficient mice exposed to irradiation showed reduced bacterial translocation and sepsis severity. Overall, our study demonstrates that MHC class Ib molecules are essential for M2b macrophage polarization and suggests that MHC class Ib molecules play an important role during infection-induced innate immunity.

The complete mitochondrial genome of grey plover Pluvialis squatarola (Charadriiformes, charadriidae).

The complete mitochondrial genome of grey plover Pluvialis squatarola was obtained by next-generation sequencing. The circular genome was 16,860 bp in length, consisting of 13 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes, and a control region. The overall nucleotide composition was A: 30.9%, T: 23.4%, C: 31.6%, G: 14.1%. Nine genes were encoded on the light strand, and the remaining 28 genes were encoded on the heavy strand. Most of the PCGs began with the ATG as the start codon, and four kinds of termination codons were used in this mitogenome. This study improves our understanding of the mitogenomic characteristics and its phylogenetic relationships within Charadriiformes.

Phylomitogenomics reconfirm the phylogenetic position of the genus Metaplax inferred from the two grapsid crabs (Decapoda: Brachyura: Grapsoidea).

Two new complete mitogenomes of the grapsids, Metaplax longipes Stimpson, 1858 and Nanosesarma minutum (De Man, 1887) were sequenced using next-generation sequencing (NGS). By analyzing a combination of 75 Brachyura taxa, our phylomitogenomic inferences suggested that Metaplax crab seperated earlier from the sesarmid crabs and closely related to the varunids with respect to Nanosesarma crab. It reconfirmed that the Metaplax should be removed from the Sesarmidae and assinged to the Varunidae. Additional mitogenomic comparisons including gene rearrangement and genomic organization were conducted among the 33 taxa of Grapsoidea and Ocypodoidea, and a shared rearrangement pattern between Metaplax longipes and the varunids were recovered, which also strongly supported the inference for the phylogenetic position of the Metaplax.

Characterization of four new mitogenomes from Ocypodoidea & Grapsoidea, and phylomitogenomic insights into thoracotreme evolution.

Four new complete mitochondrial genomes (mitogenomes) from the two superfamilies Ocypodoidea and Grapsoidea were sequenced, which represented Uca (Gelasimus) borealis (Ocypodidae: Ucinae), Dotilla wichmani (Dotillidae), Metopograpsus quadridentatus (Grapsidae: Grapsinae), and Gaetice depressus (Varunidae: Gaeticinae). All of the mitogenomes shared the complete set of 37 mitochondrial genes. Mitogenome lengths were 15,659, 15,600, 15,517, and 16,288 bp, respectively, with A + T contents of 69.41%, 68.46%, 70.30%, and 72.96%, respectively. Comparative genomic analyses suggested that they exhibited different genomic rearrangements. In particular, G. depressus shared a major rearrangement pattern present in Eriocheir crabs, while the remainder shared the brachyuran ground genomic rearrangement patterns. Phylomitogenomic inferences provided new evidence for the strongly supported nesting of Thoracotremata within Heterotremata clades. A close phylogenetic relationship was observed between Varunidae and Macrophthalmidae crabs, and between Dotillidae and Grapsidae crabs, which was consistent with mitochondrial genomic rearrangement similarities. Altogether, these results suggest the presence of reciprocal paraphyly for Ocypodoidea and Grapsoidea.