A PIXE METHOD TO STUDY BIOLOGY AT THE DNA LEVEL

An external proton beam system with a detection sensitivity of 10 g for ruthenium was used to study DNA. A metal- organic compound tris (4,7- diphenylphenanthroline) ruthenium (Ⅱ) [Ru(DiP)32-] was chosen as a metal marker. The target DNA labeled with Ru (DiP)32- was electrophoresed in an agarose gel and then was analysed by PIXE. The DNA sample with the metal marker showed clearly Ru peaks in the PIXE spectra, while the control showed no Ru peak at all. This method can be used to study biology at the DNA level.

Genetic and Metabolic Variability between Two Subspecies of <i>Chamaeleo chamaeleon</i>(Reptilia: Chamaeleonidae) in Egypt

The degree of variability between two subspecies of Chamaeleo chamaeleon;C. chamaeleon chamaeleon inhabiting El-Dabaa (MarsaMatrouh) and C. chamaeleon musae inhabiting El-Arish (North Sinai) of Egypt was investigated in this study using polyacrylamide gel electrophoreses for Lactate dehydrogenase (Ldh) and Alfa-esterase (α-Est) isoenzymes. Total lipids and proteins of liver and muscle tissues in both species were analyzed. Three Ldh isoforms were recorded for both subspecies and the activity. Rate of flow (RF) of Ldh-1 seemed to be higher in C. chamaeleon chamaeleon than in C. chamaeleon musae. This high activity could be supported by the significant increase in the total lipids and proteins in liver and muscle tissues of this species. It may thus be reasonable to suppose that C. chamaeleon chamaeleon is more active, energetic and adaptable in its habitat than C. chamaeleon musae. The α-Est showed four fractions in both subspecies. The null variations in the activity of α-Ests in the studied tissue may indicate, to some extent, the safety of the diet applied to both subspecies of chameleons.

Biochemical variability between two Egyptian <i>Stenodactylus </i>species (Reptilia: Gekkonidae) inhabiting North Sinai

Polyacrylamide gel electrophoreses for malate dehydrogenase (Mdh) and beta-esterase (β-Est) isoenzymes were conducted for biochemical differentiation between two Stenodactylus gekkonid species inhabiting North Sinai of Egypt. Total lipids and proteins of liver and muscle tissues in both species were also analyzed. A total of three Mdh isoforms were recorded in the analysis, in which the activity of Mdh-2 and Mdh-3 seemed to be higher in S. petrii than in S. sthenodactylus. This high activity could be supported by the significant increase in the total lipids and proteins in liver and muscle tissues of the species. It may thus be reasonable to suppose that S. petrii is more active, energetic and adaptable in the desert habitat than S. sthenodactylus. β-Est showed six fractions in S. petrii and only one fraction in S. sthenodactylus. It is therefore noticeable that β-Est is more highly expressed in S. petrii than in S. sthenodactylus.

Molecular Identification of Hammerhead Shark Trunks from the Southern Gulf of California using Multiplex PCR

The demand for shark fins in Asiatic markets has resulted in excessive increases in shark catches,even for species that may be under protection or subject to management.As such,it has been necessary to develop and promote monitoring efforts for exploited species and taxonomic groups in order to improve fishing management strategies for elasmobranchs.Identifying species from landings is one of many fishing management problems because landed organisms have usually already been processed and are therefore incomplete,which makes identification problematic,impedes the generation of proper species records,and leads to poor fishery assessments.Tools that can correctly identify species,such as various molecular techniques,have become essential for accurate fishery assessments.In this study,30 hammerhead trunks from artisanal fisheries from the southern portion of the Gulf of California were identified using multiplex PCR(17 Sphyrna lewini and 13 Sphyrna zygaena).The total fee to identify each trunk with this technique was~$3.80 and the procedure required 2 to 5 days.When compared with other widely-used methods,such as PCR-RFLP or barcoding,multiplex PCR is fast,efficient,low-cost,and easy to implement in a laboratory.