Project description:We contribute transcriptomic data for two species of Ostracoda, an early-diverged group of small-sized pancrustaceans. Data include new reference transcriptomes for two asexual non-marine species (Dolerocypris sinensis and Heterocypris aff. salina), as well as single-specimen transcriptomic data that served to analyse gene expression across four developmental stages in D. sinensis. Data are evaluated by computing gene expression profiles of the different developmental stages which consistently placed eggs and small larvae (at the stage of instar A-8) similar to each other, and apart from adults which were distinct from all other developmental stages but closest to large larvae (instar A-4). We further evaluated the transcriptomic data with two newly sequenced low-coverage genomes of the target species. The new data thus document the feasibility of obtaining reliable transcriptomic data from single specimens - even eggs - of these small metazoans.
Project description:Heat shock protein 70 (designated Laternula elliptica Hsp70 (LEHsp70)) expression was investigated in an Antarctic mud clam to see whether or not the inducible heat shock response has been conserved throughout over 25 million years of adaptation to constant low environmental temperatures. LEHsp70 cDNA was cloned and sequenced from the Antarctic clam Laternula elliptica. We used degenerated primers designed in the highly conserved regions of Hsp to amplify the corresponding mRNA, and full-length cDNA was obtained by rapid amplification of cDNA ends (RACE). The full length of LEHsp70 cDNA was 2470 bp, with a 5' untranslated region (UTR) of 92 bp, a 3' UTR of 416 bp, and an open reading frame (ORF) of 1962 bp encoding a polypeptide of 653 amino acids with an estimated molecular mass of 71.266 kDa and an estimated isoelectric point of 5.20. LEHsp70 contained highly conserved functional motifs of the cytosolic Hsp70 family. Expression of the LEHsp70 gene was quantified by quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) of digestive gland and gill tissues. Heat shock (10 degrees C for different time periods) caused rapid induction of LEHsp70. A significant 4.6 +/- 0.14-fold increase in the LEHsp70/beta-Actin mRNA ratio occurred in the gill at 12 hours, which returned to baseline after 48 hours. In contrast, the maximum expression in the digestive gland (3.6 +/- 0.36) was reached at 24 hours and was still significant after 48 hours (1.89 +/- 0.21). This indicates that LEHsp70 may play an important role in mediating thermal stress and tolerance in this clam.
Project description:A computationally predicted gene regulatory network (GRN), generated from mantle-specific gene expression profiles in the Antarctic clam Laternula elliptica, was interrogated to test the regulation and interaction of duplicated inducible hsp70 paralogues. hsp70A and hsp70B were identified in the GRN with each paralogue falling into unique submodules that were linked together by a single shared second neighbour. Annotations associated with the clusters in each submodule suggested that hsp70A primarily shares regulatory relationships with genes encoding ribosomal proteins, where it may have a role in protecting the ribosome under stress. hsp70B, on the other hand, interacted with a suite of genes involved in signalling pathways, including four transcription factors, cellular response to stress and the cytoskeleton. Given the contrasting submodules and associated annotations of the two hsp70 paralogues, the GRN analysis suggests that each gene is carrying out additional separate functions, as well as being involved in the traditional chaperone heat stress response, and therefore supports the hypothesis that subfunctionalization has occurred after gene duplication. The GRN was specifically produced from experiments investigating biomineralization; however, this study shows the utility of such data for investigating multiple questions concerning gene duplications, interactions and putative functions in a non-model species.
Project description:Much is known about the acquisition of phonological competence and lexical categories, but there has been substantially less research into word meaning development. In an attempt to contribute to this debate, a group of 24 children aged 4-11 were asked to define a set of words, as were a group of 12 adult controls. The stimuli included both concrete and abstract words, in particular words exhibiting a rare form of polysemy known as copredication, which permits the simultaneous attribution of concrete and abstract senses to a single nominal, creating an 'impossible' entity. The results were used to track the developmental trajectory of copredication, previously unexplored in the language acquisition literature.
Project description:The mammalian oocyte possesses powerful reprogramming factors, which can reprogram terminally differentiated germ cells (sperm) or somatic cells within a few cell cycles. Although it has been suggested that use of oocyte-derived transcripts may enhance the generation of induced pluripotent stem cells, the reprogramming factors in oocytes are undetermined, and even the identified proteins composition of oocytes is very limited. In the present study, 7,000 mouse oocytes at different developmental stages, including the germinal vesicle stage, the metaphase II (MII) stage, and the fertilized oocytes (zygotes), were collected. We successfully identified 2,781 proteins present in germinal vesicle oocytes, 2,973 proteins in MII oocytes, and 2,082 proteins in zygotes through semiquantitative MS analysis. Furthermore, the results of the bioinformatics analysis indicated that different protein compositions are correlated with oocyte characteristics at different developmental stages. For example, specific transcription factors and chromatin remodeling factors are more abundant in MII oocytes, which may be crucial for the epigenetic reprogramming of sperm or somatic nuclei. These results provided important knowledge to better understand the molecular mechanisms in early development and may improve the generation of induced pluripotent stem cells.
Project description:Bivalves from the family Lucinidae host sulfur-oxidizing bacterial symbionts, which are housed inside specialized gill epithelial cells and are assumed to be acquired from the environment. However, little is known about the Lucinidae life cycle and symbiont acquisition in the wild. Some lucinid species broadcast their gametes into the surrounding water column, however, a few have been found to externally brood their offspring by the forming gelatinous egg masses. So far, symbiont transmission has only been investigated in one species that reproduces via broadcast spawning. Here, we show that the lucinid Loripes orbiculatus from the West African coast forms egg masses and these are dominated by diverse members of the Alphaproteobacteria, Clostridia, and Gammaproteobacteria. The microbial communities of the egg masses were distinct from those in the environments surrounding lucinids, indicating that larvae may shape their associated microbiomes. The gill symbiont of the adults was undetectable in the developmental stages, supporting horizontal transmission of the symbiont with environmental symbiont acquisition after hatching from the egg masses. These results demonstrate that L. orbiculatus acquires symbionts from the environment independent of the host's reproductive strategy (brooding or broadcast spawning) and reveal previously unknown associations with microbes during lucinid early development.