DNA Sexing of the Philippine Eagle (Pithecophaga jefferyi Ogilvie-Grant) in Captivity at the Philippine Eagle Center, Davao City, Philippines

The Philippine eagle is a sexually monomorphic raptor which lacks the sex-linked morphology determining the gender especially in the juveniles. Thus, a PCR amplification technique was used to determine the sex of 24 eagles at different stages of development (2 to 37 years old) in captivity at the Philippine Eagle Center, Malagos Davao City. Fractions of the sex-linked genes, CHD-W and CHD-Z of each individual were amplified. Ka Brianne (female) and Jag (male) having 9 offspring conceived through artificial insemination were used as positive controls for sex identification of 22 other individuals. Two individuals of Gallus domesticus with confirmed genders were also included and run through PCR amplification together with the Philippine eagles using primers CHDFORNEW and CHDREVNEW to test the method. Females revealed two distinct bands (290 bp and 280 bp in size) while the males revealed only a single band of 280 bp. Eleven eagles were  found to be females while 13 were found to be  males. DNA sexing gave a 100% confirmation of the assigned sexes of the eagles, which were obtained through morphometric analysis done by personnel at the captive breeding center. DNA sexing could be a practical technique in sexing newly hatched eaglet and juveniles, naming of eagles, establishing life history characteristics, and pairing attempt or assignment of partners in the threatened avian species such as the Philippine eagles

Phylogenetic relationships among megachiropteran species from the two major islands of the Philippines, deduced from DNA sequences of the cytochrome b gene

Abstract: Complete cytochrome b gene sequences (1140 base pairs) in species of Megachiroptera were ascertained in order to deduce their phylogenetic relationships, using samples of Cynopterus brachyotis, Eonycteris spelaea, Ptenochirus jagori, Pteropus vampyrus, and Rousettus amplexicaudatus collected from the islands of Luzon and Mindanao in the Philippines. Genetic divergence between samples of R. amplexicaudatus, E. spelaea, and C. brachyotis was very small. On the other hand, a large genetic distance was detected between species of Megachiroptera. The phylogenetic tree using neighbor-joining, parsimony, and maximum-likelihood methods generated similar topologies, reflecting the evolutionary associations among megachiropteran species. We estimated that Megachiroptera separated from Microchiroptera 50.2 million years ago (MYA), and split further approximately 32.4 MYA, forming three lineages: E. spelaea, R. amplexicaudatus, and P. vampyrus and the P. jagori -C. brachyotis cluster. The third lineage, composed of P. vampyrus and the P. jagori -C. brachyotis cluster, branched out 31.9 MYA. We hypothesize that R. amplexicaudatus diverged from the three members of the subfamily Pteropodinae examined, and its phylogenetic relationship with E. spelaea remains unclear

Genetic and Molecular Analysis of Wild-Derived Arrhythmic Mice

A new circadian variant was isolated by screening the intercross offspring of wild-caught mice (Mus musculus castaneus). This variant was characterized by an initial maintenance of damped oscillations and subsequent loss of rhythmicity after being transferred from light-dark (LD) cycles to constant darkness (DD). To map the genes responsible for the persistence of rhythmicity (circadian ratio) and the length of free-running period (τ), quantitative trait locus (QTL) analysis was performed using F2 mice obtained from an F1 cross between the circadian variant and C57BL/6J mice. As a result, a significant QTL with a main effect for circadian ratio (Arrhythmicity; Arrh-1) was mapped on Chromosome (Chr) 8. For τ, four significant QTLs, Short free-running period (Sfp-1) (Chr 1), Sfp-2 (Chr 6), Sfp-3 (Chr 8), Sfp-4 (Chr 11) were determined. An epistatic interaction was detected between Chr 3 (Arrh-2) and Chr 5 (Arrh-3). An in situ hybridization study of clock genes and mouse Period1::luciferase (mPer1::luc) real-time monitoring analysis in the suprachiasmatic nucleus (SCN) suggested that arrhythmicity in this variant might not be attributed to core circadian mechanisms in the SCN neurons. Our strategy using wild-derived variant mice may provide a novel opportunity to evaluate circadian and its related disorders in human that arise from the interaction between multiple variant genes