Menopause in nonhuman primates?

A gradual alteration in the mechanisms underlying reproduction and fertility characterizes the aging process in human females. These changes culminate in menopause, conventionally defined as a cessation of menstrual cycles that marks the end of reproductive capacity. In fact, a central and defining event in menopause is the discontinuation of ovulation, which is correlated with a number of structural and functional changes in the reproductive axis. Despite several decades of research, a degree of uncertainty remains as to whether nonhuman primates undergo menopause, and whether they are suitable models of human reproductive senescence. We review some of the controversies that have clouded our understanding of reproductive aging in nonhuman primates, including issues of definition, timing, comparability of data from wild versus captive populations, and cross-species comparisons. The existing data support the view that menopause occurs in a number of primate species and is not unique to humans.     

Is the Guadeloupean racoon (Procyon minor) really an endemic species? New insights from molecular and chromosomal analyses

The Guadeloupean racoon has been chosen as the emblematic species of the Parc National de Guadeloupe because of its supposed endemic specificity. However, its taxonomic position is not clearly defined. At what period did this animal colonize Guadeloupe and how it reached the island remain unsolved questions. To clarify these points, insular and continental individuals (Procyon lotor), coming from five localities and belonging to three subspecies, were compared using molecular (sequencing of a 294-bp of the left domain of the mtDNA control region) and chromosomal (C, G and R karyotypes) analyses. Genetic distance between the Guadeloupean racoon and lotor subspecies from Virginia and Maryland was very short (mean sequence divergence between haplotypes equals to 1.46%). A four times higher distance was found between P. l. lotor and P. l. pallidus, a continental subspecies inhabiting Arizona than between P. l. lotor and Procyon minor. A neighbour-joining phenogram is proposed; the Guadeloupean haplotype is on a branch close to the one clustering P. l. lotor from the East coast whereas the haplotype from Arizona diverged earlier. These results strongly suggest that the Guadeloupean racoon is included in the P. lotor species. Moreover, no differences were found between P. lotor and P. minor karyotypes, again suggesting a high genetic homogeneity between the two taxa. Furthermore, comparison of the control region variability within Procyon with intra- and interspecific variability observed in other Carnivores, clearly strengthens the hypothesis that P. minor is conspecific with P. lotor. These results imply that the taxonomic status of the Guadeloupean racoon should be revised. In a biogeographic perspective, it is suggested that the racoon has been recently introduced in Guadeloupe by man with individuals coming from the east coast of the USA. The consequences of these results for conservation of the racoon in Guadeloupe, and more generally, the definition and the use of the subspecies as a unit of conservation are discussed.     

Does enemy damage vary across the range of exotic plant species? Evidence from two coastal dune plant species in eastern Australia

Oecologia - Release from natural enemies is often cited as a key factor for understanding the success of invasive plant species in novel environments. However, with time invasive species will...     

Can captivity lead to inter-species mating in two Mesocricetus hamster species?

In two closely related species, females generally prefer conspecific males over heterospecific males. We found that estrous (but not diestrous) female Syrian hamsters Mesocricetus auratus prefer the odors of conspecific males to odors of Turkish hamsters Mesocricetus brandti . However, female Syrian hamsters are not aggressive toward male Turkish hamsters and will readily mate with them. We hypothesize that many generations in captivity led to a reduction in females' ability to avoid inter-species mating, possibly related to the heightened sexual receptivity observed in Mesocricetus hamsters in captivity. To test this hypothesis, we replicated a study carried out with female Turkish hamsters soon after the current laboratory stock of this species was established. In that study, female Turkish hamsters showed lordosis toward male Syrian hamsters in only 20% of interactions and attacked heterospecific males in 80% of the pairings. Using animals descended from that original colony (after many generations in captivity and certain episodes of inbreeding), 100% of female Turkish hamsters mated with heterospecific males and none showed aggression toward heterospecific males. Thus female avoidance of inter-specific mating may be affected by captive rearing conditions.     

Are New Zealand's Nothofagus species in equilibrium with their environment?

Abstract. Past explanations of the large disjunctions in the distribution of New Zealand's four Nothofagus species have emphasized displacement during glacial cycles followed by slow re-occupation of suitable sites, or the effects of plate tectonics coupled with ecological and/or environmental limitations to further spread. In this study the degree of equilibrium between Nothofagus distribution and environment was compared with that of other widespread tree species by statistical analysis. Generalized additive regression models were used to relate species distribution data to estimates of temperature, solar radiation, soil water deficit, atmospheric humidity, lithology and drainage. For each species, the amount of spatial patterning remaining unexplained by environment was assessed by adding a variable describing species presence/absence on adjacent plots. Results indicate that Nothofagus species occur more frequently in environments suboptimal for tree growth, i.e. having various combinations of cool temperatures, low winter solar radiation, high root-zone water deficit, low humidity, and infertile granitic substrates. Despite these demonstrated preferences, they exhibit substantially more spatial clustering which is unexplained by environment, than most other widespread tree species. Predictions formed from regressions using environment alone confirm that several major Nothofagus disjunctions are not explicable in terms of the environmental factors used in this analysis, but more likely reflect the effects of historic displacement coupled with slowness to invade forest dominated by more rapidly dispersing endomycorrhizal species. The technique used in this study for detecting residual spatial autocorrelation after fitting explanatory variables has potentially wide application in other studies where either regression or ordination techniques are used for analysis of compositional data.     

Is Didymosphenia geminata an introduced species in New Zealand? Evidence from trends in water chemistry,and chloroplast DNA

Defining the geographic origins of free‐living aquatic microorganisms can be problematic because many such organisms have ubiquitous distributions, and proving absence from a region is practically impossible. Geographic origins become important if microorganisms have invasive characteristics. The freshwater diatom Didymosphenia geminata is a potentially ubiquitous microorganism for which the recent global expansion of nuisance proliferations has been attributed to environmental change. The changes may include declines in dissolved reactive phosphorus (DRP) to low levels (e.g., <2 mg/m³) and increases in dissolved inorganic nitrogen (DIN) to >10 mg/m³ because both these nutrient conditions are associated with nuisance proliferations of D. geminata. Proliferations of D. geminata have been observed in South Island, New Zealand, since 2004. We aimed to address the ubiquity hypothesis for D. geminata in New Zealand using historical river water nutrient data and new molecular analyses. We used 15 years of data at 77 river sites to assess whether trends in DRP or DIN prior to the spread of D. geminata were consistent with a transition from a rare, undetected, species to a nuisance species. We used new sequences of chloroplast regions to examine the genetic similarity of D. geminata populations from New Zealand and six overseas locations. We found no evidence for declines in DRP concentrations since 1989 that could explain the spread of proliferations since 2004. At some affected sites, lowest DRP occurred before 2004. Trends in DIN also did not indicate enhanced suitability for D. geminata. Lack of diversity in the chloroplast intergenic regions of New Zealand populations and populations from western North America is consistent with recent dispersal to New Zealand. Our analyses did not support the proposal that D. geminata was historically present in New Zealand rivers. These results provide further evidence countering proposals of general ubiquity in freshwater diatoms and indicate that, as assumed in 2004, D. geminata is a recent arrival in New Zealand.     

Characterization of β2-microglobulin transcripts from two teleost species

Using degenerate primers based on published ₂-microglobulin sequences we were able to obtain an expected 111 base pairs (bp) polymerase chain reaction (PCR) fragment from tilapia genomic DNA. The sequence of this fragment showed a high degree of similarity to mouse ₂-microglobulin at the protein level. We used these primers in an anchored PCR to obtain a 213 bp PCR fragment from a carp cDNA library. This was then used to clone a full-length ₂-microglobulin cDNA from carp. The carp sequence showed the highest similarity to rabbit ₂-microglobulin. Both sequences showed strong similarities to all previously published vertebrate ₂-microglobulin sequences. The predicted protein secondary structure of both the carp and tilapia clones was almost identical to the corresponding regions of previously known vertebrate ₂-microglobulin protein sequences. When either the carp or tilapia probes were used against corresponding northern blots, they hybridized to a message of approximately 800–1000 bases long, which corresponds to the previously published lengths of ₂-microglobulin mRNAs. Southern blotting indicated that ₂-microglobulin was encoded by a single copy gene in both cases. Phylogenetic analysis indicated that the sequences were related to the ₂-microglobulins of higher vertebrates but grouped together in an ancestral position.The nucleotide sequence data reported in this paper have been submitted to the GenBank nucleotide sequence database and have been assigned the accession numbers L05536 (carp), L05537 (tilapia).     

Plant species microendemism and conservation of montane maquis in New Caledonia: two new species of Pancheria (Cunoniaceae) from the Roche Ouaïème

Two species of Pancheria (Cunoniaceae) described here, Pancheria minima J.C. Bradford and Pancheria ouaiemensis J.C. Bradford, draw attention to a recently recognized biodiversity pattern in New Caledonia. Montane maquis on acidic substrates, especially on the Roche Ouaïème, harbors numerous endemic species and is a rare and globally unique ecosystem. We cite 12 species, most described in the past several years, known only from the Roche Ouaïème in an area less than 10km². Overall, 27 species are known only from montane maquis and currently not found in a well-protected area. The major local threat to montane maquis habitat is anthropogenic fire, with climate change a possible long-term problem. Those montane maquis species known from one or two localities, occupying very small areas, and with declining habitat quality are critically endangered or endangered based on IUCN Red List criteria. Adding the Roche Ouaïème to the reserve system of New Caledonia is recommended to protect and manage a representative area of montane maquis on acidic substrates. A research strategy is proposed to identify species most at risk, locate possible unknown areas of montane maquis, and update taxonomic knowledge. A review of characters that vary among Pancheria species is provided, and the inflorescence architecture is described and diagramed. Both new Pancheria species occur at upper elevations in shrubby habitats. P. minima is remarkable in that the size of plants, leaves and reproductive parts is highly reduced compared to other known species.     

Does divergence in female mate choice affect male size distributions in two cave fish populations?

Sexual selection by female choice can maintain male traits that are counter selected by natural selection. Alteration of the potential for sexual selection can thus lead to shifts in the expression of male traits. We investigated female mate choice for large male body size in a fish (Poecilia mexicana) that, besides surface streams, also inhabits two caves. All four populations investigated, exhibited an ancestral visual preference for large males. However, only one of the cave populations also expressed this female preference in darkness. Hence, the lack of expression of female preference in darkness in the other cave population leads to relaxation of sexual selection for large male body size. While P. mexicana populations with size-specific female mate choice are characterized by a pronounced male size variation, the absence of female choice in one cave coincides with the absence of large bodied males in that population. Our results suggest that population differences in the potential for sexual selection may affect male trait variation.     

Are olfactory cues involved in nest recognition in two social species of estrildid finches?

Reliably recognizing their own nest provides parents with a necessary skill to invest time and resources efficiently in raising their offspring and thereby maximising their own reproductive success. Studies investigating nest recognition in adult birds have focused mainly on visual cues of the nest or the nest site and acoustic cues of the nestlings. To determine whether adult songbirds also use olfaction for nest recognition, we investigated the use of olfactory nest cues for two estrildid finch species, zebra finches (Taeniopygia guttata) and Bengalese finches (Lonchura striata var. domestica) during the nestling and fledgling phase of their offspring. We found similar behavioural responses to nest odours in both songbird species. Females preferred the odour of their own nest over a control and avoided the foreign conspecific nest scent over a control during the nestling phase of their offspring, but when given the own odour and the foreign conspecific odour simultaneously we did not find a preference for the own nest odour. Males of both species did not show any preferences at all. The behavioural reaction to any nest odour decreased after fledging of the offspring. Our results show that only females show a behavioural response to olfactory nest cues, indicating that the use of olfactory cues for nest recognition seems to be sex-specific and dependent on the developmental stage of the offspring. Although estrildid finches are known to use visual and acoustic cues for nest recognition, the similar behavioural pattern of both species indicates that at least females gain additional information by olfactory nest cues during the nestling phase of their offspring. Thus olfactory cues might be important in general, even in situations in which visual and acoustic cues are known to be sufficient.     

Are adaptive loci transferable across genomes of related species? Outlier and environmental association analyses in Alpine Brassicaceae species

Local adaptation is one possible response of organisms to survive in a changing environment. However, the genetic basis of adaptation is not well understood, especially in nonmodel species. To infer recurrent patterns of local adaptation, we investigated whether the same putative adaptive loci reoccur in related species. We performed genome scans using amplified fragment length polymorphism (AFLP) markers on populations of five Alpine Brassicaceae species sampled across a wide range of environmental conditions. To identify markers potentially under directional selection, we performed outlier and environmental association analyses using a set of topo‐climatic variables available as GIS layers. Several AFLP loci showed signatures of adaptation, of which one, found in Cardamine resedifolia (Cre_P1_212.5), was associated with precipitation. We sequence‐characterized this candidate locus and genotyped single nucleotide polymorphisms (SNPs) found within this locus for all species. Testing for environmental associations of SNPs revealed the same association of this locus in Arabis alpina but not in other study species. Cumulative statistical evidence indicates that locus Cre_P1_212.5 is environmentally relevant or is linked to a gene under selection in our study range. Furthermore, the locus shows an association to the same potentially selective factor in at least one other related species. These findings help to identify trends in plant adaptation in Alpine ecosystems in response to particular environmental parameters.     

Do exaggerated sexual swellings function in female mating competition in primates? A comparative test of the reliable indicator hypothesis

The reliable indicator hypothesis proposes that exaggeratedsexual swellings in female primates serve as honest signalsof female quality that function in female—female competitionover mates. We examined a version of this hypothesis usinginterspecific data to test whether exaggerated sexual swellingsare associated with female mating competition, as measured usingthe adult sex ratio, female canine size, and expected femalemating synchrony. The ratio of females to males and relativecanine size declined over evolutionary transitions in swellingstate, thus providing no support for the reliable indicatorhypothesis. Expected female mating synchrony increased over evolutionary transitions in swelling state, but this patterndid not approach significance, and the patterns were oppositeto predictions when controlling for the number of males inthe group. In addition to these comparative tests, we reviewedevidence concerning individual attributes of females relativeto characteristics of their swellings. Contrary to the reliableindicator hypothesis, the least fertile females, or those leastlikely to raise surviving offspring, often have larger swellings.We consider the statistical power of our tests, discuss thetheoretical and empirical bases for our comparative predictions,and consider other lines of evidence needed to test the reliableindicator hypothesis. We also discuss an alternative hypothesis, the graded signal hypothesis, which combines the benefits ofbiasing and confusing paternity through a novel mechanism andis testable in the field and the laboratory.     

Tuber aestivum and Tuber uncinatum: two morphotypes or two species?

Tuber spp. are ectomycorrhizal fungi that establish symbioses with shrubs and trees. Because of their different smell and taste, Tuber uncinatum and Tuber aestivum are two truffle morphotypes with a different market value, but whether or not T. uncinatum and T. aestivum are different taxa is still an open debate among mycologists. In order to identify molecular keys characterizing both T. aestivum and T. uncinatum morphotypes, ITS/RFLPs analyses were carried out on a large collection of samples from all over Italy and from other European countries, followed by a study of the phylogenesis of ITS, beta-tubulin and EF 1-alpha genes, on representative samples. The present study provides compelling evidence that: (i) T. uncinatum and T. aestivum belong to the same species, (ii) neither morphotype presents a specific molecular fingerprint, but they may even share identical alleles at any of the loci analysed; (iii) T. aestivum is most likely under a selfing reproductive mode. Our findings suggest that ecological, rather than genetic causes may account for differences in sporal morphology, taste and smell between T. aestivum and T. uncinatum truffles.     

Revision of two species of ?Ulocrinus and a new pelecocrinid crinoid from West Timor

Two cladid crinoid species, ?Ulocrinus indicus Wanner, 1924, and ?Ulocrinus conoideus Wanner, 1937, are reinterpreted as cladid crinoids that do not belong to the cromyocrinids. This justifies Wanner's questioning of the generic assignment. ?Ulocrinus indicus has bifascial radial facets and is considered an advanced intermediate dendrocrinid assigned to the incertae superfamiliae, Katerocrinidae n. fam., Katerocrinus indicus n. gen., n. comb. This extends the range of the bifascial dendrocrinids upward into the Permian. ?Ulocrinus conoideus has trifascial radial facets and is assigned to the superfamily Scytalocrinoidea, incertae familiae, Dochmocrinus conoideus n. gen., n. comb. It re-emphasizes the need for revision of the family Scytalocrinidae. An unnamed, poorly preserved cup is described and considered to be a pelecocrinid crinoid, thus adding to the diversity of the West Timor Permian crinoids.