Short tail stories: the hirudin-like factors HLF6 and HLF7 of the Asian medicinal leech, Hirudinaria manillensis

The leech-derived hirudins and hirudin-like factors (HLFs) share a common molecule structure: a short N-terminus, a central globular domain, and an elongated C-terminal tail. All parts are important for function. HLF6 and HLF7 were identified in the Asian medicinal leech, Hirudinaria manillensis. The genes of both factors encode putative splice variants that differ in length and composition of their respective C-terminal tails. In either case, the tails are considerably shorter compared to hirudins. Here we describe the functional analyses of the natural splice variants and of synthetic variants that comprise an altered N-terminus and/or a modified central globular domain. All natural splice variants of HLF6 and HLF7 display no detectable thrombin-inhibitory potency. In contrast, some synthetic variants effectively inhibit thrombin, even with tails as short as six amino acid residues in length. Our data indicate that size and composition of the C-terminal tail of hirudins and HLFs can vary in a great extent, yet the full protein may still retain the ability to inhibit thrombin.

Genetic diversity of H’mong short tail dog based on sequencing of the D-loop hypervariable -1 region (HV1)

The H'mong short tail dog is breed indigenous dogs, distributed in mountainousareas of northern Vietnam. H'mong short tail dog possesses many valuable properties such as intelligence, agility, good health, good shape, human friendliness, ease of training and it can fully meet the needs of war Dogs intelligence, strength, good parenting, people friendly and more importantly, still keeping wild characteristics of hunting dogs. The total 45 samples (blood) collected from 45 individuals in two provinces of Northern Vietnam (Ha Giang and Lao Cai), were used to assess genetic diversity based on sequencing hypervariable – 1 region (HV1) in D-loop genes. In the current study showed that genetic diversity of H'mong short tail dog was high with nucleotide diversity (Pi = 0.00801), haplotype diversity (Hd = 0.96162) and average number of nucleotide differences (Kt = 5.18384). Furthermore, 25 different haplotypes were recorded and divided into four main groups: A, B, C, and E. Of which, seven new haplotypes in haplogroups A (An1 to An7) and 18 haplotypes have been published in the world. In addition, H'mong short tail dog was found rare haplogroups (B1, C2, E1 and E4). Notably, there is none individuals contain haplotype of haplogroups (D and F). H'mong short tail dog were identified 38 single nucleotide polymorphisms, including 32 nucleotide base substitution/base insertion and 6 nucleotide indel mutation. Almost mutation was transversion (31/32) and only one nucleotide transition mutations. Phylogenetic tree shown that H'mong short tail dog have close relationship with dogs origin from East Asia (China, Japan and Korea).

A new passeriform (Aves: Passeriformes) from the early Oligocene of Poland sheds light on the beginnings of Suboscines

The paper describes a complete specimen of a passerine bird from the early Oligocene of Poland, preserved as imprints of bones and feathers on two slabs. Crosnoornis nargizia gen. et sp. nov. is just the fifth passerine species described from the Paleogene worldwide and the fourth complete. The features preserved in the distal elements of the wing exclude Acanthisittidae and Oscines and indicate that this bird can be included in Suboscines, making it the second complete representative of this group in the Paleogene. A strong, straight beak indicates that this bird could feed on a variety of foods, including hard seeds, fruit and invertebrates, and, therefore, occupied a different foraging niche than the Oligocene passerines described so far. The wing proportions, a very short tail and relatively long legs indicate that this bird spent most of its time in the forest, close to the ground in dense shrubs or dense tree crowns.

Ubiquity, Diversity, and Genomic Complexity of Cyanophages in Freshwater Environments

Cyanophages are viruses that infect cyanobacteria (also known as blue-green algae) and are ubiquitious in marine and freshwater environments. In recent years, freshwater cyanophages have attracted more attention because they can affect global freshwater ecosystems. The spatial distribution and morphological diversity of cyanophage populations were examined in Lake Donghu with three trophic regions: hypertrophic, eutrophic, and mesotrophic regions. The surprisingly high viral abundance (ranging from 108 to 109 phage mL−1) and morphological diversity were detected. Most of them have tails and belong to the families Siphoviridae, Myoviridae, and Podoviridae. Various morphotypes were observed, such as prolate-headed virus-like particles and lemon-shaped virus-like particles. In addition, some cyanophages were studied by virological experiments and whole-genome analyses, combined with morphological observation. For example, three cyanophages were isolated and their whole genomes were sequenced. Contractile tail myonophage MaMV-DC infects bloom-forming cyanobacterium Microcystis aeruginosa. Tailless cyanophage Planktothrix agardhii virus isolated from Lake Donghu (PaV-LD) infects filamentous cyanobacterium. Short-tail podovirus A-4L can infect the model cyanobacterium Anabaena sp. strain PCC 7120. The MaMV-DC genome contains 169,223 bp encoding 170 putative open reading frames (ORFs). The PaV-LD genome posseses 95,299 bp encoding 142 putative ORFs. The genome of short-tail podovirus A-4L has 41,750 bp encoding 38 putative ORFs. There are significant differences in their genomic size and encoded tail proteins, but all three cyanophages contain genes that are not commonly found in phages. By studying the vast biodiversity of viruses in freshwater environments, these novel findings of cyanophages broaden our insights, and allow us to gain more useful knowledge about the global impact of these viruses in freshwater ecosystems.