Ecology and Protein Composition of Polypedates leucomystax (Gravenhorst, 1829) (Anura: Rhacophoridae) Foam Nests from Peninsular Malaysia

Abstract

The four-lined tree frog, Polypedates leucomystax, spawns its eggs in a moist structure called a foam nest. Four foam nests constructed by this species were collected from the Sungai Sedim Recreational Forest, Kedah, Peninsular Malaysia. Two foam nests were found deposited on the leaves of low vegetation hanging over a rock pool. One was attached inside a water tank, and one was found on grass near an ephemeral puddle. In the laboratory, the foam nests were freeze-dried and the protein concentrations quantified, fractionated, and analyzed using LC-MS/MS. Twenty-two

Review on antimicrobial peptides from Malaysian amphibian resources: status, research approaches and ways forward

“…Malaysian (Sarawak) frog species' skin secretions showed that some of the frog species contain AMPs and some are more potent than others (Sabri et al, 2018;Shahabuddin et al, 2018). Brevinin-2 has been identified from protein profiling of a foam nest from Polypedates leucomystax (Shahrudin et al, 2017) At least five studies have been performed on extralimital frog species that can also be found in Malaysia, Table 2, (Lu et al, 2008;Song et al, 2009;Al-Ghaferi et al, 2010;Wang et al, 2012;Suhyana et al, 2015). Skin secretions of Limnonectes kuhlii, Kuhl's wart frog, from China revealed that the five novel AMPs that were purified and characterised showed strong antimicrobial effects Gram-positive and Gram-negative bacteria and fungi (Wang et al, 2012a).…”

“…Amphibians produce skin secretions when they feel threatened/stressed due to their host defence mechanism (Hancock and Sahl, 2006). Zahri et al (2015) and Shahrudin et al (2017) directly collected secretions without stimulation because parotoid secretions and foam nests do not need any stimulant for collection. These secretions were collected either by immersing the animals in a low concentration, salt solution (sodium chloride or sodium acetate) or directly rinsing the animals with deionised water.…”

“…An extraction buffer was the most common method utilised to extract and purify peptides in previous studies. These extraction buffers can either be phosphate (Lu et al, 2008;Song et al, 2009;Wang et al, 2012a;Suhyana et al, 2015) or Tris-HCl (Dahham et al, 2016;Shahrudin et al, 2017). The extraction buffer acts as a lysis buffer that improves the protein molecules' stability, as they can easily be denatured,…”

“…Identification and structural characterisation of AMPs are essential to specify their properties. Only two studies have identified AMPs; one focused on AMPs of skin secretions and the other on AMPs from foam nests (Conlon et al, 2008;Shahrudin et al, 2017). A protein profiling analysis of P. asper skin secretions revealed more than 50 proteins, and some were undiscovered in the available database (Dahham et al, 2016 (Inger et al, 2017;Norhayati, 2017).…”

“…Most AMPs are synthesised and stored within the secretory glands, commonly known as the poison glands in the skin of anurans. However, AMPs can also be found within the stomach, gastric mucus, blood, internal organs, eggs, tadpoles and foam nests (Moore et al, 1991;Duellman and Trueb, 1994;Nicolas and Mor, 1995;Bullet et al, 2004;Conlon et al, 2004;Wells, 2007;Han et al, 2008;Shahrudin et al, 2017). Toxic secretions that contain AMPs and proactive substances are expelled onto the skin surface when the animal is injured, stressed or threatened (Simmaco et al, 1998).…”