Gonadal sex differentiation and development during early ontogenesis in the breeding kisslip cuttlefish (Sepia lycidas)

To understand and obtain basic information on sex differentiation in the kisslip cuttlefish (Sepia lycidas), the gonadal sex differentiation process was investigated histologically. An undifferentiated gonad consisting of germ cells and somatic cells was found to form at a caudal site in the space between the internal yolk sacks of cuttlefish embryos at 14 and 21 days after spawning (DAS). Sexual dimorphism in the gonad was first detected at around 28 DAS. Meiotic oocytes were observed as the first visible morphological characteristic of ovaries in the gonads of some cuttlefish embryos at 28 DAS. In other individuals, neither meiotic germ cells,nor the appearance of a testicular structure, were observed in the gonad even after 10 days post hatching (DPH). Seminiferous tubules, consisting of a small number of spermatogonia and a surrounding basement membrane,were the first visible morphological characteristic of the testis in the male gonad, detected at around 20 DPH. This is the third report on the gonadal sex differentiation process in cephalopods

Anti-haemostatic compounds from the vampire snail Cumia reticulata: Molecular cloning and in-silico structure-function analysis

Blood-feeding animals are known for their ability to produce bioactive compounds to impair haemostasis and suppress pain perception in the host. These compounds are extremely appealing for pharmacological development since they are generally very effective and specific for their molecular target. A preliminary RNA-Seq based characterization of the secretion from salivary and mid-oesophageal tissues of the vampire snail Cumia reticulata, revealed a complex mixture of feeding-related transcripts with potential anaesthetic and anticoagulant action. Based on the cloned full-length mRNAs, it was possible to verify the sequence of five genes encoding haematophagy-related products. The in silico modelled three-dimensional structure of each translational product was analysed to gain information on their potential biochemical activity. We have hereby validated and further investigated the assembled transcripts presumably involved in the antihaemostatic action, to improve our comprehensive understanding of this subset of the feeding secretion. The studied proteins included both inhibitors of primary haemostasis such as the vWFA domain-containing proteins, and compounds targeting different steps of the coagulation cascade, as e.g. the Turripeptide-like/protease inhibitor, the TFPI-like multiple Kunitz-type protease inhibitors, the Meprin-like metalloproteases and the Astacin/ShKT-like domain-containing proteins. All these molecules showed promising potential for pharmacological development