New record of Kashmir Birch Mouse Sicista concolor leathemi (Thomas, 1893) (Rodentia: Sminthidae) in the Indian Himalaya

Birch mice are grouped under the monotypic genus Sicista Gray, 1827 and placed under the family Sminthidae. They are distributed over the Palearctic ream and the fragmented population of the species Sicista concolor reported from China, North Pakistan and India in Himalayan region. The present communication is a range extension of the Kashmir Birch mouse, Sicista concolor leathemi in Indian Himalaya and first report from Himachal Pradesh.

Evidence of unidirectional gene flow in a fragmented population of Salmo trutta L.

Selection, genetic drift, and gene flow affect genetic variation within populations and genetic differences among populations. Both drift and selection tend to decrease variation within populations and increase differences among populations, whereas gene flow increases variation within populations but leads to populations being related. In brown trout (Salmo trutta L.), the most important factor in population fragmentation is disrupted river-segment connectivity. The main goal of the study was to use genetic analysis to estimate the level of gene flow among resident and migratory brown trout in potential hybridization areas located downstream of impassable barriers in one river basin in the southern Baltic Sea region. First, spawning redds were counted in the upper river basin downstream of impassable barriers. Next, samples were collected from juveniles in spawning areas located downstream of barriers and from adults downstream and upstream of barriers. Subsequently, genetic analysis was performed using a panel of 13 microsatellite loci and the Salmo trutta 5 K SNP microarray. The genetic differentiation estimated between the resident form sampled upstream of the barriers and the anadromous specimens downstream of the barriers was high and significant. Analysis revealed that gene flow occurred between the two forms in the hybridization zone investigated and that isolated resident specimens shared spawning grounds with sea trout downstream of the barriers. The brown trout population from the river system investigated was slightly, internally diversified in the area accessible to migration. Simultaneously, the isolated part of the population was very different from that in the rest of the basin. The spawning areas of the anadromous form located downstream of the barriers were in a hybridization zone and gene flow was confirmed to be unidirectional. Although they constituted a small percentage, the genotypes typical upstream of the barriers were admixed downstream of them. The lack of genotypes noted upstream of the barriers among adult anadromous individuals might indicate that migrants of upstream origin and hybrids preferred residency.

Mitochondrial OMA1 and OPA1 as Gatekeepers of Organellar Structure/Function and Cellular Stress Response

Mammalian mitochondria are emerging as a critical stress-responsive contributor to cellular life/death and developmental outcomes. Maintained as an organellar network distributed throughout the cell, mitochondria respond to cellular stimuli and stresses through highly sensitive structural dynamics, particularly in energetically demanding cell settings such as cardiac and muscle tissues. Fusion allows individual mitochondria to form an interconnected reticular network, while fission divides the network into a collection of vesicular organelles. Crucially,opticatrophy-1(OPA1) directly links mitochondrial structure and bioenergetic function: when the transmembrane potential across the inner membrane (ΔΨm) is intact, long L-OPA1 isoforms carry out fusion of the mitochondrial inner membrane. When ΔΨmis lost, L-OPA1 is cleaved to short, fusion-inactive S-OPA1 isoforms by the stress-sensitive OMA1 metalloprotease, causing the mitochondrial network to collapse to a fragmented population of organelles. This proteolytic mechanism provides sensitive regulation of organellar structure/function but also engages directly with apoptotic factors as a major mechanism of mitochondrial participation in cellular stress response. Furthermore, emerging evidence suggests that this proteolytic mechanism may have critical importance for cell developmental programs, particularly in cardiac, neuronal, and stem cell settings. OMA1’s role as a key mitochondrial stress-sensitive protease motivates exciting new questions regarding its mechanistic regulation and interactions, as well as its broader importance through involvement in apoptotic, stress response, and developmental pathways.

Increased individual homozygosity is correlated with low fitness in a fragmented lizard population

Isolation owing to anthropogenic habitat fragmentation is expected to increase the homozygosity of individuals, which might reduce their fitness as a result of inbreeding depression. Using samples from a fragmented population of the lizard Psammodromus algirus, for which we had data about two correlates of fitness, we genotyped individuals for six microsatellite loci that correctly capture genome-wide individual homozygosity of these lizards (as validated with an independent sample of lizards genotyped for both these microsatellites and > 70 000 single nucleotide polymorphisms). Our data revealed genetic structure at a very small geographical scale, which was compatible with restricted gene flow among populations disconnected in a matrix of inhospitable habitat. Lizards from the same fragment were genetically more related to one another than expected by chance, and individual homozygosity was greater in small than in large fragments. Within fragments, individual homozygosity was negatively associated with adult body size and clutch mass, revealing a link among reduced gene flow, increased homozygosity and lowered fitness that might reduce population viability deterministically. Our results contribute to mounting evidence of the impact of the loss of genetic diversity on fragmented wild populations.

Effects of Landscape Fragmentation on Genetic Diversity of Male-Biased Dioecious Plant Pistacia chinensis Bunge Populations

Pistacia chinensis Bunge (Anacardiaceae) is a dioecious woody plant of significant economic values that is used in traditional Chinese Medicine as well as for wood production. More importantly, it is one of the ideal tree species for bio-diesel production because of the high oil content in its seeds. In this study, we aim to reveal the effects of landscape fragmentation on the genetic diversity (GD) of the dioecious plant Pistacia chinensis populations. A total of nine microsatellites were used to genotype 180 P. chinensis individuals from six populations to estimate the differences in GD between different populations. The study revealed that genetic diversity of the P. chinensis population as a whole is relatively high in the Thousand-Island Lake (TIL) region, but its fragmented landscape still led to the loss of rare alleles, especially in a fragmented small population, a post-fragmented population, and a male population. The partitioning of a large continuous population into small isolated remnant patches led to the direct loss of genetic diversity and, subsequently, because of the mediated gene flow of seeds and pollen, genetic drift, and the spatial distribution of existing plants, the GD gradually decreased. The restricted gene flow and the increase in self-pollination and inbreeding impaired the population’s long-term development. Therefore, the wild P. chinensis populations in the TIL region needs effective protective measures, including foreign artificial pollination and seedling transplantations.

Senyumia granitica (Gesneriaceae) from Johor, Malaysia, the second species of Senyumia

The genus Senyumia was previously known from a single species, S.minutiflora (Ridl.) Kiew, A.Weber & B.L.Burtt, from a limestone karst, Gunung Senyum, in Pahang, Malaysia. Senyumiagranitica Kiew, here described and illustrated, is the second species of the genus. It differs from S.minutiflora, not only in its habitat, but also in its shorter leaves, larger, non-resupinate or only partially resupinate flowers and smaller seeds. It is known from a small, fragmented population from a low range of hills. Therefore, under the IUCN Red List Categories & Criteria, it is assessed as Critically Endangered.

Complete mitochondrial genome of the Western Capercaillie Tetrao urogallus (Phasianidae, Tetraoninae)

The Western Capercaillie (Tetrao urogallus) is a galliform bird of boreal climax forests from Scandinavia to eastern Siberia, with a fragmented population in southwestern Europe. We extracted the DNA of T. urogallus aquitanicus and obtained the complete mitochondrial genome (mitogenome) sequence by combining Illumina and Sanger sequencing sequence data. The mitochondrial genome of T. urogallus is 16,683 bp long and is very similar to that of Lyrurus tetrix (16,677 bp). The T. urogallus mitogenome contains the normal 13 protein-coding genes (PCGs), 22 transfer RNAs, 2 ribosomal RNAs, and the control region. The number, order, and orientation of the mitochondrial genes are the same as in L. tetrix and in other species of the same and other bird families. The three domains of the control region contained conserved sequences (ETAS; CSBs), boxes (F, E, D, C, B, BS box), the putative origin of replication of the H-strand (OH) and bidirectional promoters of translation (LSP/HSP).