Comparative Aspects if the Ecology of Four Syntopic Species of Angle-Headed Lizards, Genus Gonocephalus

Gonocephalus is a genus of arboreal agamid lizards, endemic to south-east Asia. Four syntopic species of Gonocephalus have been recorded in the lowlands of Sarawak- G. doriae, G. bornensis, G. liogaster and G. grandis. Most are associated with tree trunks, saplings and shrubs, sometimes occurring in syntopy. Morphologically similar and closely related species living in sympatry tend to avoid niche overlap by differing in one or more aspects of their ecology, which are presumably caused, maintained and/or reinforced by interspecific competition. Successful partition of resources within a system, thus, is vital in reducing competition and increasing feeding efficiency, thus facilitates coexistence. Ecological theory dictates that spatial, trophic and temporal dimensions are the main dimensions of ecological space. The four species of Gonocephalus can be broadly similar in their biology, so the question raised was, are there striking differences in their respective ecologies? Studies on comparative ecology at Kubah National Park has been ongoing since June 2018. The objectives of this study were to test whether tropical lizards partition resources spatially and trophically? In addition, we wanted to understand the thermal biology, habitat preference and home range of these species. Structural and thermal microhabitat characteristics were recorded. Stomach contents of individuals were removed via stomach flushing for identification to ordinal level. Temperature-sensitive radio transmitters were attached for 10–14 weeks to the dorsum of pelvic girdle of at least 16 individuals (that weigh over 27 gm) for thermal and home range studies. Towards the end of this project, new ecological data for the syntopic species of Gonocephalus are expected, of potential value for conservation and management

Herpetology 2024: Which lizard?

The article enumerates the lizard fauna of Borneo, and depicts the interesting species to be encountered by the participants of the 10th World Congress of Herpetology

Predation on Gonocephalus liogaster (Agamidae) by Ptyas carinata (Colubridae) in Sarawak, Borneo

Gonocephalus liogaster (Günther, 1872) is a large, forest-dwelling lizard, inhabiting lowland rainforests and peat swamp forests of Sundaland (Das, 2006). They are often found perching on tree trunks during the day and sleep clinging onto slender tree branches, their heads directed towards the trunk at night. This sleeping behaviour is commonly seen in many arboreal lizards to enhance detecting and subsequently avoiding nocturnal predators (Mohanty et al., 2016). Despite these strategies, lizards are often mentioned as prey of snakes. Within the genus, G. chamaeleontinus (Laurenti, 1768) has been reported as prey of the cat snake, Boiga drapiezii (Boie, 1827) (Cegalerba and Szwemberg, n.d.) in Sumatra, Indonesia

CYRTODACTYLUS CONSOBRINUS (Peters’ Bent-toed Gecko)

A field observation on attempted predation by the gekkonid, Cyrtodactylus consobrinus on spider eggs is made

AMPHIBIANS AND REPTILES

Chapter provides an inventory of the herpetofauna of Samunsam Wildlife Sanctuary, Sarawak, east Malaysia

Cellular FLICE-inhibitory protein is required for T cell survival and cycling

Fas-associated death domain (FADD) and caspase-8 are key signal transducers for death receptor–induced apoptosis, whereas cellular FLICE-inhibitory protein (cFLIP) antagonizes this process. Interestingly, FADD and caspase-8 also play a role in T cell development and T cell receptor (TCR)–mediated proliferative responses. To investigate the underlying mechanism, we generated cFLIP-deficient T cells by reconstituting Rag−/− blastocysts with cFLIP-deficient embryonic stem cells. These Rag chimeric mutant mice (rcFLIP−/−) had severely reduced numbers of T cells in the thymus, lymph nodes, and spleen, although mature T lymphocytes did develop. Similar to FADD- or caspase-8–deficient cells, rcFLIP−/− T cells were impaired in proliferation in response to TCR stimulation. Further investigation revealed that cFLIP is required for T cell survival, as well as T cell cycling in response to TCR stimulation. Interestingly, some signaling pathways from the TCR complex appeared competent, as CD3 plus CD28 cross-linking was capable of activating the ERK pathway in rcFLIP−/− T cells. We demonstrate an essential role for cFLIP in T cell function

Cellular FLICE-inhibitory protein is required for T cell survival and cycling

Fas-associated death domain (FADD) and caspase-8 are key signal transducers for death receptor–induced apoptosis, whereas cellular FLICE-inhibitory protein (cFLIP) antagonizes this process. Interestingly, FADD and caspase-8 also play a role in T cell development and T cell receptor (TCR)–mediated proliferative responses. To investigate the underlying mechanism, we generated cFLIP-deficient T cells by reconstituting Rag−/− blastocysts with cFLIP-deficient embryonic stem cells. These Rag chimeric mutant mice (rcFLIP−/−) had severely reduced numbers of T cells in the thymus, lymph nodes, and spleen, although mature T lymphocytes did develop. Similar to FADD- or caspase-8–deficient cells, rcFLIP−/− T cells were impaired in proliferation in response to TCR stimulation. Further investigation revealed that cFLIP is required for T cell survival, as well as T cell cycling in response to TCR stimulation. Interestingly, some signaling pathways from the TCR complex appeared competent, as CD3 plus CD28 cross-linking was capable of activating the ERK pathway in rcFLIP−/− T cells. We demonstrate an essential role for cFLIP in T cell function

Shewanella Phage Encoding a Putative Anti-crispr-Like Gene Represents a Novel Potential Viral Family

Shewanella is a prevalent bacterial genus in deep-sea environments including marine sediments, exhibiting diverse metabolic capabilities that indicate its significant contributions to the marine biogeochemical cycles. However, only a few Shewanella phages were isolated and deposited in the NCBI database. In this study, we report the isolation and characterization of a novel Shewanella phage, vB_SbaS_Y11, that infects Shewanella KR11 and was isolated from the sewage in Qingdao, China. Transmission electron microscopy revealed that vB_SbaS_Y11 has an icosahedral head and a long tail. The genome of vB_SbaS_Y11 is a linear, double-stranded DNA with a length of 62,799 bp and a G+C content of 46.9%, encoding 71 putative open reading frames. No tRNA genes or integrase-related feature genes were identified. An uncharacterized anti-CRISPR AcrVA2 gene was detected in its genome. Phylogenetic analysis based on the amino acid sequences of whole genomes and comparative genomic analyses indicate that vB_SbaS_Y11 has a novel genomic architecture and shares low similarity to Pseudomonas virus H66 and Pseudomonas phage F116. vB_SbaS_Y11 represents a potential new family-level virus cluster with eight metagenomic assembled viral genomes named Ranviridae. IMPORTANCE The Gram-negative Shewanella bacterial genus currently includes about 80 species of mostly aquatic Gammaproteobacteria, which were isolated around the globe in a multitude of environments, such as freshwater, seawater, coastal sediments, and the deepest trenches. Here, we present a Shewanella phage vB_SbaS_Y11 that contains an uncharacterized anti-CRISPR AcrVA2 gene and belongs to a potential virus family, Ranviridae. This study will enhance the knowledge about the genome, diversity, taxonomic classification, and global distribution of Shewanella phage populations