Molecular identification and phylogenetic position of Cuora yunnanensis

The Yunnan box turtle (Cuora yunnanensis, Boulenger, 1906), which has drawn much attention in conservation biology, was regarded as extinct since it was previously known only from 12 specimens collected in Yunnan, China, before 1908. Recently, live specimens have been discovered which are suggested to be C. yunnanensis. To determine whether the newly discovered specimens are really C. yunnanensis, we have established a molecular phylogeny, with a 1725-bp fragment of mitochondrial DNA, using samples from three live individuals of C. yunnanensis, together with sequence data from a museum specimen of C. yunnanensis (MNHN 1907.10) and other members of the genus Cuora. We found that the three newly discovered individuals and the old museum specimen of C. yunnanensis are very similar both in morphology and in mitochondrial DNA sequence, suggesting that the three new individuals are the very C. yunnanensis, and thus the species is not extinct. Our phylogenetic analysis also demonstrates that C. yunnanensis is not of recent hybrid origin, but rather represents a distinct evolutionary lineage.

Molecular analysis of the sex chromosomes of the platyfish Xiphophorus maculatus: Towards the identification of a new type of master sexual regulator in vertebrates

In contrast to mammals and birds,fish display an amazing diversity of genetic sex determination systems,with frequent changes during evolution possibly associated with the emergence of new sex chromosomes and sex-determining genes.To better understand the molecular and evolutionary mechanisms driving this diversity,several fish models are studied in parallel.Besides the medaka(Oryzias latipes Temminck and Schlegel,1846)for which the master sex-determination gene has been identified,one of the most advanced models for studying sex determination is the Southern platyfish(Xiphophorus maculatus,Günther 1966).Xiphophorus maculatus belongs to the Poeciliids,a family of live-bearing freshwater fish,including platyfish,swordtails and guppies that perfectly illustrates the diversity of genetic sex-determination mechanisms observed in teleosts.For X.maculatus,bacterial artificial chro-mosome contigs covering the sex-determination region of the X and Y sex chromosomes have been constructed.Initial molecular analysis demonstrated that the sex-determination region is very unstable and frequently undergoes duplications,deletions,inversions and other rearrangements.Eleven gene candidates linked to the master sex-determining gene have been identified,some of them corresponding to pseudogenes.All putative genes are present on both the X and the Y chromosomes,suggesting a poor degree of differentiation and a young evolutionary age for platyfish sex chromosomes.When compared with other fish and tetrapod genomes,syntenies were detected only with autosomes.This observation supports an independent origin of sex chromosomes,not only in different vertebrate lineages but also between different fish species.

Myxomycetes from Papua New Guinea and New Caledonia

We present a compilation of all myxomycetes recorded from Papua New Guinea(PNG)and New Caledonia(NC).Specimens were collected during field trips in September 1983–January 1984 to both territories and in August 1991,October 2007,and April 2009 to NC.Bark and dung samples for moist chamber cultures were collected during the field trips in September 1983–January 1984(PNG and NC)and in August 1991 and October 2007(NC).In addition,information from previous publications and unpublished specimens in the herbarium at the Plant Protection Instituted in Port Moresby,PNG,are included.A total of 180 species are reported.Of the 63 species from PNG 51 are new to the country,and 123 of the 149 species from NC are new to the territory.