Marked colour divergence in gliding membranes of a tropical lizard mirror population differences in the colour of falling leaves

Populations of the Bornean gliding lizard, Draco cornutus, differ markedly in the colour of their gliding membranes. They also differ in local vegetation type (mangrove forest versus lowland rainforest) and consequently, the colour of falling leaves (red and brown/black in mangrove versus green, brown and black in rainforest). We show that the gliding membranes of these lizards closely match the colours of freshly fallen leaves in the local habitat as they appear to the visual system of birds (their probable predators). Furthermore, gliding membranes more closely resembled colours of local fallen leaves than standing foliage or fallen leaves in the other population’s habitat. This suggests that the two populations have diverged in gliding membrane coloration to match the colours of their local falling leaves, and that mimicking falling leaves is an adaptation that functions to reduce predation by birds

Ornament size and colour as alternative strategies for effective communication in gliding lizards

Sexual ornamentation needs to be conspicuous to be effective in attracting potential mates and defending territories and indeed, a multitude of ways exists to achieve this. Two principal mechanisms for increasing conspicuousness are to increase the ornament's colour or brightness contrast against the background and to increase the size of the ornament. We assessed the relationship between the colour and size of the dewlap, a large extendible throat-fan, across a range of species of gliding lizards (Agamidae; genus Draco) from Malaysia and the Philippines. We found a negative relationship across species between colour contrast against the background and dewlap size in males, but not in females, suggesting that males of different species use increasing colour contrast and dewlap size as alternative strategies for effective communication. Male dewlap size also increases with increasing sexual size dimorphism, and dewlap colour and brightness contrast increase with increasing sexual dichromatism in colour and brightness, respectively, suggesting that sexual selection may act on both dewlap size and colour. We further found evidence that relative predation intensity, as measured from predator attacks on models placed in the field, may play a role in the choice of strategy (high chromatic contrast or large dewlap area) a species employs. More broadly, these results highlight that each component in a signal (such as colour or size) may be influenced by different selection pressures and that by assessing components individually, we can gain a greater understanding of the evolution of signal diversity

Structure of the gene encoding the human leukocyte adhesion molecule-1 (TQ1, Leu-8) of lymphocytes and neutrophils.

The leukocyte adhesion molecule-1 (LAM-1, TQ1, Leu-8), expressed by human lymphocytes, neutrophils, monocytes, and their precursors, is a member of the selectin family of cellular adhesion/homing receptors which play important roles in leukocyte-endothelial cell interactions. These cell surface molecules contain an amino-terminal lectin-like domain followed by an epidermal growth factor-like domain and a variable number of short consensus repeat sequences similar to those found in C3/C4 binding proteins. In this report, the structure of the lyam-1 gene that encodes the LAM-1 protein was determined by isolating overlapping genomic DNA clones that hybridized with a LAM-1 cDNA probe. The lyam-1 gene spans greater than 30 kilo base pairs of DNA and is composed of at least 10 exons. The 5' end of the LAM-1 mRNA was mapped by primer extension analysis revealing a single initiation region for transcription. Exons II through X contain translated sequences; exon II encodes the translation initiation codon; exon III, the leader peptide; IV, the lectin-like domain; V, the epidermal growth factor-like domain; VI and VII, the short consensus repeat units; exon VIII, the transmembrane region; exon IX encodes seven amino acids containing a potential phosphorylation site; and exon X encodes the five remaining amino acids of the cytoplasmic tail and the long 3' untranslated region. Sequencing of LAM-1 cDNA clones derived from neutrophils revealed that the protein expressed by neutrophils would be identical in sequence with the protein expressed by lymphocytes and cDNAs that would encode different isoforms of LAM-1 protein were not detected. In addition, the level of LAM-1 expression by lymphocytes and neutrophils from two patients with paroxysmal nocturnal hemoglobinuria, a disorder in which linkage of phosphatidylinositol anchors to proteins is defective, was similar to that of normal controls. Therefore, the usage of exons II through X results in the generation of a single major LAM-1 protein product expressed by lymphocytes and neutrophils

Soluble Sema4D in Plasma of Head and Neck Squamous Cell Carcinoma Patients Is Associated With Underlying Non-Inflamed Tumor Profile

Semaphorin 4D (Sema4D) is a glycoprotein that is expressed by several tumors and immune cells. It can function as a membrane bound protein or as a cleaved soluble protein (sSema4D). We sought to investigate the translational potential of plasma sSema4D as an immune marker in plasma of patients with head and neck squamous cell carcinoma (HNSCC). Paired peripheral blood and tumor tissue samples of 104 patients with HNSCC were collected at the same time point to allow for real time analysis. Scoring of the histological inflammatory subtype (HIS) was carried out using Sema4D immunohistochemistry on the tumor tissue. sSema4D was detected in plasma using direct ELISA assay. Defining elevated sSema4D as values above the 95th percentile in healthy controls, our data showed that sSema4D levels in plasma were elevated in 25.0% (95% CI, 16.7–34.9%) of the patients with HNSCC and showed significant association with HIS immune excluded (HIS-IE) (p = 0.007), Sema4D+ve tumor cells (TCs) (p = 0.018) and PD-L1+ve immune cells (ICs) (p = 0.038). A multi-variable logistic regression analysis showed that HIS was significantly (P = 0.004) associated with elevated sSema4D, an association not explained by available patient-level factors. Using the IO-360 nanoString platform, differential gene expression (DGE) analysis of 10 HNSCC tumor tissues showed that patients with high sSema4D in plasma (HsS4D) clustered as IFN-γ negative tumor immune signature and were mostly HIS-IE. The IC type in the HsS4D paired tumor tissue was predominantly myeloid, while the lymphoid compartment was higher in the low sSema4D (LsS4D). The Wnt signaling pathway was upregulated in the HsS4D group. Further analysis using the IO-360, 770 gene set, showed significant non-inflamed profile of the HsS4D tumors compared to the LsS4D. In conclusion, our data reveals an association between sSema4D and the histological inflammatory subtype. © Copyright © 2021 Younis, Ghita, Elnaggar, Chaisuparat, Theofilou, Dyalram, Ord, Davila, Tallon, Papadimitriou, Webb, Bentzen and Lubek