Progesterone impairs social recognition in male rats

The influence of progesterone in the brain and on the behavior of females is fairly well understood. However, less is known about the effect of progesterone in the male system. In male rats, receptors for progesterone are present in virtually all vasopressin (AVP) immunoreactive cells in the bed nucleus of the stria terminalis (BST) and the medial amygdala (MeA). This colocalization functions to regulate AVP expression, as progesterone and/or progestin receptors (PR)s suppress AVP expression in these same extrahypothalamic regions in the brain. These data suggest that progesterone may influence AVP-dependent behavior. While AVP is implicated in numerous behavioral and physiological functions in rodents, AVP appears essential for social recognition of conspecifics. Therefore, we examined the effects of progesterone on social recognition. We report that progesterone plays an important role in modulating social recognition in the male brain, as progesterone treatment leads to a significant impairment of social recognition in male rats. Moreover, progesterone appears to act on PRs to impair social recognition, as progesterone impairment of social recognition is blocked by a PR antagonist, RU-486. Social recognition is also impaired by a specific progestin agonist, R5020. Interestingly, we show that progesterone does not interfere with either general memory or olfactory processes, suggesting that progesterone seems critically important to social recognition memory. These data provide strong evidence that physiological levels of progesterone can have an important impact on social behavior in male rats.     

Episomal maintenance of a bovine papilloma virus vector in transgenic mice.

We have used a bovine papillomavirus-based vector to generate transgenic mice. Transgenic mice result from either pronuclear or cytoplasmic injections of the vector into fertilized eggs. Of 30 mice generated by microinjection, 27 (90%) contained the vector in its episomal form, at less than one copy per cell. This represents a highly efficient means of gene transfer in which the transgene is in a controlled genetic environment.     

Distance,elevation and environment as drivers of diversity and divergence in bumble bees across latitude and altitude

Identifying drivers of dispersal limitation and genetic differentiation is a key goal in biogeography. We examine patterns of population connectivity and genetic diversity using restriction site‐associated DNA sequencing (RADseq) in two bumble bee species, Bombus vosnesenskii and Bombus bifarius, across latitude and altitude in mountain ranges from California, Oregon and Washington, U.S.A. Bombus vosnesenskii, which occurs across a broader elevational range at most latitudes, exhibits little population structure while B. bifarius, which occupies a relatively narrow higher elevation niche across most latitudes, exhibits much stronger population differentiation, although gene flow in both species is best explained by isolation with environmental niche resistance. A relationship between elevational habitat breadth and genetic diversity is also apparent, with B. vosnesenskii exhibiting relatively consistent levels of genetic diversity across its range, while B. bifarius has reduced genetic diversity at low latitudes, where it is restricted to high‐elevation habitat. The results of this study highlight the importance of the intersect between elevational range and habitat suitability in influencing population connectivity and suggest that future climate warming will have a fragmenting effect even on populations that are presently well connected, as they track their thermal niches upward in montane systems.     

Changes from pasture to a native tree plantation affect soil organic matter in a tropical soil,Panamá

Background and aims

We examined changes in soil organic matter arising from conversion of a 45-year old pasture to a 10 yr. old native tree plantation in Panamá, to evaluate the effect of monoculture and mixtures.

Methods

We intensively sampled the soil 0–10 cm depth in the pasture in 2001 and in 22 plantation plots in 2011, ranging from 5 monocultures to 3- and 6-species treatments; samples were also taken from an undisturbed forest site. Soil analyses included organic carbon (SOC) and δ¹³C.

Results

Conversion of the pasture to tree plantation resulted in an overall loss of SOC of 0.6 kg m^?2 (18%) in the top 10 cm, but neither tree species nor diversity had a significant effect. End-member δ¹³C values suggested that the contribution of C₃ plants to SOC was increased from 26% in the pasture to 55% after 10 years of plantation and SOC turnover times were calculated to be 21–36 yr.

Conclusions

The magnitude of the loss in soil SOC is smaller than the increases in tree biomass (~3 kg C m^?2) and litter (~0.3 kg C m^?2) in the plantation, but still a significant part of the ecosystem C balance.

     

First known satellite collaring of a viverrid species: preliminary performance and implications of GPS tracking Malay civets (<Emphasis Type="Italic">Viverra tangalunga</Emphasis>)

The application of advanced technologies to the study of little-known species is a necessary step in generating effective conservation strategies. Despite the biological importance of the small carnivore guild, a paucity of data exists in terms of the spatial ecology of these species, largely due to logistical constraints of large and bulky collar units. This study reports the first known satellite collaring of a viverrid, the Malay civet (Viverra tangalunga), in Sabah, Malaysian Borneo. Stationary tests of two generations of 65–70 g e-obs GmbH ‘Collar 1A’ units recorded high fix success rates and good accuracy and precision under semi-open canopy. From October 2013–August 2015, nine adult V. tangalunga were fit with e-obs collars recording hourly nocturnal GPS locations. Collars were successfully deployed for 27–187 days. Field GPS fix success varied from 22 to 88.3 %, with the study documenting a total GPS success of 58.1 % across all individuals. Despite this large in-field performance range, the quality and quantity of data collected by these units surpass that of previous VHF studies on Asian viverrids, collecting on average a 16-fold increase in locations per collaring day. The successful application of satellite technology to these little-known carnivores carries significant biological and conservation implications, and it is recommended that satellite collars are a viable technology to conduct detailed and well-designed ecological studies of Viverridae species.