Unraveling phylogenetic relationships and species boundaries in the arid adapted Gerbillus rodents (Muridae: Gerbillinae) by RAD-seq data.

Gerbillus is one of the most speciose genera among rodents, with ca. 51 recognized species. Previous attempts to reconstruct the evolutionary history of Gerbillus mainly relied on the mitochondrial cyt-b marker as a source of phylogenetic information. In this study, we utilize RAD-seq genomic data from 37 specimens representing 11 species to reconstruct the phylogenetic tree for Gerbillus, applying concatenation and coalescence methods. We identified four highly supported clades corresponding to the traditionally recognized subgenera: Dipodillus, Gerbillus, Hendecapleura and Monodia. Only two uncertain branches were detected in the resulting trees, with one leading to diversification of the main lineages in the genus, recognized by quartet sampling analysis as uncertain due to possible introgression. We also examined species boundaries for four pairs of sister taxa, including potentially new species from Morocco, using SNAPP. The results strongly supported a speciation model in which all taxa are treated as separate species. The dating analyses confirmed the Plio-Pleistocene diversification of the genus, with the uncertain branch coinciding with the beginning of aridification of the Sahara at the the Plio-Pleistocene boundary. This study aligns well with the earlier analyses based on the cyt-b marker, reaffirming its suitability as an adequate marker for estimating genetic diversity in Gerbillus.

Common Factors of Alzheimer's Disease and Rheumatoid Arthritis-Pathomechanism and Treatment.

The accumulation of amyloid plaques, or misfolded fragments of proteins, leads to the development of a condition known as amyloidosis, which is clinically recognized as a systemic disease. Amyloidosis plays a special role in the pathogenesis of neurodegenerative diseases such as Alzheimer's disease (AD), Parkinson's disease, and rheumatoid arthritis (RA). The occurrence of amyloidosis correlates with the aging process of the organism, and since nowadays, old age is determined by the comfort of functioning and the elimination of unpleasant disease symptoms in the elderly, exposure to this subject is justified. In Alzheimer's disease, amyloid plaques negatively affect glutaminergic and cholinergic transmission and loss of sympathetic protein, while in RA, amyloids stimulated by the activity of the immune system affect the degradation of the osteoarticular bond. The following monograph draws attention to the over-reactivity of the immune system in AD and RA, describes the functionality of the blood-brain barrier as an intermediary medium between RA and AD, and indicates the direction of research to date, focusing on determining the relationship and the cause-effect link between these disorders. The paper presents possible directions for the treatment of amyloidosis, with particular emphasis on innovative therapies.

Derived woodiness and annual habit evolved in African umbellifers as alternative solutions for coping with drought.

BACKGROUND: One of the major trends in angiosperm evolution was the shift from woody to herbaceous habit. However, reversals known as derived woodiness have also been reported in numerous, distantly related clades. Among theories evoked to explain the factors promoting the evolution of derived woodiness are moderate climate theory and cavitation theory. The first assumes that woody habit evolves in response to mild climate allowing for prolonged life span, which in turn leads to bigger and woodier bodies. The second sees woodiness as a result of natural selection for higher cavitation resistance in seasonally dry environments. Here, we compare climatic niches of woody and herbaceous, mostly southern African, umbellifers from the Lefebvrea clade to assess whether woody taxa in fact occur in markedly drier habitats. We also calibrate their phylogeny to estimate when derived woodiness evolved. Finally, we describe the wood anatomy of selected woody and herbaceous taxa to see if life forms are linked to any particular wood traits. RESULTS: The evolution of derived woodiness in chamaephytes and phanerophytes as well as the shifts to short-lived annual therophytes in the Lefebvrea clade took place at roughly the same time: in the Late Miocene during a trend of global climate aridification. Climatic niches of woody and herbaceous genera from the Cape Floristic Region overlap. There are only two genera with distinctly different climatic preferences: they are herbaceous and occur outside of the Cape Floristic Region. Therefore, studied herbs have an overall climatic niche wider than their woody cousins. Woody and herbaceous species do not differ in qualitative wood anatomy, which is more affected by stem architecture and, probably, reproductive strategy than by habit. CONCLUSIONS: Palaeodrought was likely a stimulus for the evolution of derived woodiness in the Lefebvrea clade, supporting the cavitation theory. The concurrent evolution of short-lived annuals withering before summer exemplifies an alternative solution to the same problem of drought-induced cavitation. Changes of the life form were most likely neither spurred nor precluded by any qualitative wood traits, which in turn are more affected by internode length and probably also reproductive strategy.

Role of the Intestinal Microbiome, Intestinal Barrier and Psychobiotics in Depression.

The intestinal microbiota plays an important role in the pathophysiology of depression. As determined, the microbiota influences the shaping and modulation of the functioning of the gut-brain axis. The intestinal microbiota has a significant impact on processes related to neurotransmitter synthesis, the myelination of neurons in the prefrontal cortex, and is also involved in the development of the amygdala and hippocampus. Intestinal bacteria are also a source of vitamins, the deficiency of which is believed to be related to the response to antidepressant therapy and may lead to exacerbation of depressive symptoms. Additionally, it is known that, in periods of excessive activation of stress reactions, the immune system also plays an important role, negatively affecting the tightness of the intestinal barrier and intestinal microflora. In this review, we have summarized the role of the gut microbiota, its metabolites, and diet in susceptibility to depression. We also describe abnormalities in the functioning of the intestinal barrier caused by increased activity of the immune system in response to stressors. Moreover, the presented study discusses the role of psychobiotics in the prevention and treatment of depression through their influence on the intestinal barrier, immune processes, and functioning of the nervous system.

Effects of vitamin B1 (thiamine) deficiency in lake trout (Salvelinus namaycush) alevins at hatching stage.

The objectives of this study were to examine the relationship between thiamine concentrations in unfertilized eggs and yolksac individuals of lake trout (Salvelinus namaycush), along with any associated histopathological changes in the tissues of alevins at the hatching stage. We address these questions in a lake trout population from different spawning grounds of Lake Michigan (North and South), known for compromised survival due to early mortality syndrome (EMS). However, a dichotomous forage base of lake trout spawning stocks, with a dietary thiaminase-rich alewife in the North, and dietary low-thiaminase round goby in the South, provides the basis for the assumption that different diets may lead to differences in severity of EMS between different stocks. Lake trout eggs of 18 females were collected and fertilized individually with the sperm of several males. The eggs, eyed embryos and newly-hatched alevins were sampled to examine thiamine utilization during embryogenesis. Progenies of females with low (< 0.73 nmol/g) and high (> 0.85 nmol/g) levels of thiamine were chosen for histological studies. The obtained results showed that total thiamine levels in the body and yolk of eyed embryos and alevins at hatching were influenced by thiamine levels of unfertilized eggs and it decreased during embryogenesis (to 51% in eyed embryos and 28% in newly-hatched alevins in comparison to unfertilized eggs). The survival of lake trout until hatching stage does not correlate with the thiamine level, however it was affected by collection site and was significantly higher in fish from the South site (Julian's Reef). At the hatching stage, no pathological changes were observed in the brain, olfactory lobe, retina or liver in embryos regardless of thiamine concentrations in unfertilized eggs. It has been concluded that an enhanced thiamine requirement for the fast muscle mass growth near the swim-up stage is responsible for overt and histopathological signs of EMS. Current study confirms earlier findings that lake trout suffering from EMS can be successfully treated by immersion in thiamine solution as late as at the swim-up stage.