Tracing paternal ancestry in mice, using the Y-linked, sex-determining locus, Sry

The molecular evolution of mammalian Y-linked DNA sequences is of special interest because of their unique mode of inheritance: most Y- linked sequences are clonally inherited from father to son. Here we investigate the use of Y-linked sequences for phylogenetic inference. We describe a comparative analysis of a 515-bp region from the male sex- determining locus, Sry, in 22 murine rodents (subfamily Murinae, family Muridae), including representatives from nine species of Mus, and from two additional murine genera--Mastomys and Hylomyscus. Percent sequence divergence was < 0.01% for comparisons between populations within a species and was 0.19%-8.16% for comparisons between species. Our phylogenetic analysis of 12 murine taxa resulted in a single most- parsimonius tree that is highly concordant with phylogenies based on mitochondrial DNA and allozymes. A total evidence tree based on the combined data from Sry, mitochondrial DNA, and allozymes supports (1) the monophyly of the subgenus Mus, (2) its division into a Palearctic group (M. musculus, M. domesticus, M. spicilegus, M. Macedonicus, and M. spretus) and an Oriental group (M. cookii++, M. cervicolor, and M. caroli), and (3) sister-group relationships between M. spicilegus and M. macedonicus and between M. cookii and M. cervicolor. We argue that Y- chromosome DNA sequences represent a valuable new source of characters for phylogenetic inference.      

Dissimilarity between prostaglandin E1 and nitric oxide donors as potentiators of plasma exudation in the rabbit skin in vivo

The ability of prostaglandin E₁ (PGE₁) and nitric oxide (NO) donor compounds such as sodium nitroprusside (SNP), glyceryl trinitrate (GTN), and 3-morpholino-sydnonimine (SIN-1) to modulate the histamine- and bradykinin-induced increase in microvascular permeability have been investigated in rabbit skin. The effect of the NO synthesis inhibitor N^ω-nitro- -arginine methyl ester ( -NAME) on the plasma exudation induced by histamine and bradykinin was also studied. Local edema formation was evaluated using [¹²⁵I]human serum albumin. New Zealand white rabbits received an intravenous injection of [¹²⁵I]human albumin followed immediately by the intradermal injection of edematogenic agents into the shaved dorsolateral skin. PGE₁ (0.1 nmol/site) significantly potentiated both histamine- and bradykinin-induced edema. In contrast, SNP (0.4–400 nmol/site), SIN-1 (0.4–400 nmol/site), and GTN (0.4–40 nmol/site) did not affect the edematogenic response induced by either histamine or bradykinin. GTN (0.4–40 nmol/site) also had no effect on the increase in plasma exudation induced by histamine and bradykinin in the presence of PGE₁. -NAME (50–400 nmol/site), but not its enantiomer -NAME, dose-dependently reduced the edema formation induced by a combination of either histamine or bradykinin with PGE₁. This inhibition was significantly reversed by SNP (4–400 nmol/site) and by high doses (2.5 μmol/site) of -arginine (but not by -arginine). Our results thus demonstrate that PGE₁, but not nitrovasodilators, can actually potentiate histamine- and bradykinin-induced edema in rabbit skin. This discrepancy cannot be explained by the lack of vasodilator activity of the nitrovasodilators since these were able to reverse the -NAME-induced inhibition of the edema provoked by histamine. Rather, this difference most likely reflects the ability of PGE₁ to modulate vascular permeability by mechanism(s) other than an increase in arterial flow.     

Le ionophore A23187

The acrosomic status of spermatozoa prepared for IVF has been evaluated by means of immunofluorescence test from Fenichel and Hsi using calcium A 23187 ionophore as inductor of acrosome reaction (AR). The spontaneous AR remains slight, even after 6 hour-incubation in Menezo B2 (6,8+2,7%). The response to ionophore, moderate before (11,2+9%), frankly increases after a 6h-capacitation (28,9+8,3%) in a group of 25 IVF couples (tubal indication, normal semen, positive fertilization). Nevertheless, it remains slight or null in 4 cases of unexplained repeated failure of fertilization. The response to ionophore A 23187 allows to explore the kinetics of capacitation of spermatozoa and their ability to perform AR. Its significance in terms of fecondance remains to be precised.     

Beyond the green: assessing quarry restoration success through plant and beetle communities

In assessing the effectiveness of ecological restoration actions, outcomes evaluation using a multi‐taxa approach can greatly contribute to a clearer understanding of their success/failure. Since comprehensive biodiversity assessments are rarely possible, choosing taxa groups that are indicative of the ecosystem's structural and functional recovery is of major importance. Our goal was to evaluate the success of revegetation actions performed in a Mediterranean limestone quarry, using plants and epigean beetles as indicators. We compared their abundance, diversity, and community composition between revegetated sites aged 5, 13, and 19 years and a natural reference. Total plant cover significantly increased with restoration age and quickly reached reference values. However, native woody species cover dropped in the oldest site, while non‐native species became dominant. The abundance of beetles was always lower in restoration sites when compared to the reference, increasing with age, although not significantly. The richness of both plant species and beetle families was lower in restoration sites and did not show any trend towards the reference values. Finally, using nonmetric multidimensional scaling, the composition of plant and beetle communities from restoration sites showed a clear separation from the reference. Restoration efforts have successfully modified post‐quarry sites, but considerable differences remain, probably largely related to the use of the non‐native species Pinus halepensis in restoration plans. P. halepensis high cover in restoration sites greatly affects the structure of the ecosystem, and most likely its functioning too, as well as related ecosystem services, causing divergence from the reference values and compromising restoration success.