Eufrocina P. Atabay

Field survey on Tamaraw(Bubalus mindorensis) - Present population size and herd behavior in wild

Abstract Tamaraw, an endemic species on the Philippine island of Mindoro, is a critically endangered animal listed by IUCN. Although the population size of tamaraw has been monitored by the Department of Environment and Natural Resources of the Philippines annually from 1999, there is no academic report on the wild tamaraw population. Therefore, we investigated the present tamaraw population size and herd behavior in their natural habitat. The study area covered about 4,000 ha of natural grassland located in Mts. Iglit-Baco National Park, with 16 strategically located observation sites. The tamaraw population was counted using the Intensive Concentration Count Method or Simultaneous Multi Vantage Point Counts for five consecutive days in April, 2006. Fresh fecal samples of tamaraws were also collected from seven observation sites to determine prevalence of endoparasites. A total of 263 individuals were observed, consisting of 162 adult (62%), 52 juveniles (estimated ages of 1-4 years: 20%) and 49 yearlings (19%). Out of the 263 individuals, 29 (11%) were observed solitary, of which the majority were adult males (15/29). On the other hand, the remaining 234 tamaraws formed 71 groups consisting of 2-7 head per group. Out of 65 groups successfully sexed for adult animals, 63 (93%) had one or two adult cows with or without calves and 36 (55%) had one adult bull. From 15 fresh fecal samples, Coccidia eggs were detected in 10 cases and Fasciola eggs in 3 cases. These results demonstrated that 1) the tamaraw population is still in the critical ranges and there is a considerable deviation in the sex ratio of adult animals and in the proportion of juveniles to yearlings, 2) the tamaraw usually form families consisting of one bull with one or two cows, with the consequence of some solitary bulls, and 3) further analysis is required on the prevalence of endoparasites in the tamaraw.

Incidence of chromosomal abnormalities in early-stage river buffalo embryos derived from in vitro fertilization.

Abstract: The present study focused on determining the incidence of chromosomal abnormalities in river buffalo embryos produced in vitro to reveal the causes of the low conception rate of transferred embryos. River buffalo oocytes were collected from 2- to 8-mm ovarian follicles of slaughtered river buffaloes in the Philippines and India, matured in vitro, and inseminated with frozen-thawed river buffalo spermatozoa at a final concentration of 1 × 106 sperm/ml. At 36–40 h of in vitro culture, 2- to 8-cell stage embryos were treated with vinblastine sulphate for 6 to 10h, and prepared as chromosomal samples. The rate of chromosomally normal embryos (diploidy 2n = 50) was 52.2% (48/92), while the incidence of chromosomal abnormalities reached 47.8% (44/92) in the analyzed embryos. Polyploidy was the most frequent abnormality (22 embryos; 23.9%), while the incidences of mixoploid (11 embryos, 12%) and haploid embryos (11 embryos, 12%) were the same. The polyploidy and mixoploidy observed in the present study may be the result of polyspermy. The early-stage river buffalo embryos derived from in vitro production displayed a high incidence of chromosomal abnormalities that might affect their subsequent development.

Molecular Characterization and Comparison of Phospholipase C zeta (PLCZ1) Gene Between Swamp (Bubalus carabanensis) and Riverine (Bubalus bubalis) Buffaloes: Its Implications and Future Perspectives

ABSTRACT Phospholipase C zeta, a novel sperm-specific protein which is widely known to induce oocyte activation following fertilization, had already been characterized in various mammalian species, but not in water buffaloes thus far. The present study was conducted to initially characterize and compare the sequences of PLCZ1 gene of swamp and riverine buffaloes. Semen samples were collected; total RNA was extracted and reverse-transcribed. PLCZ1 cDNA was then amplified, and submitted for sequencing. Buffalo PLCZ1 gene yielded a sequence of 1905 base pair nucleotides translated into 634 bp amino acids. In general, the buffalo PLCZ1 gene was found to have high sequence identity with cattle and other domestic species. Similarly, significant residues and motifs in PLCZ1 gene sequence are found conserved in water buffaloes. However, there are variations in sequences identified between types of water buffaloes that may play a role in species-specific differences in terms of gene and protein expression, physiological mechanisms, and biological functions. The molecular information on buffalo PLCZ1 gene is highly valuable in subsequent works such as correlation studies on the identified gene variations with semen quality and fertility, and the development of biomarkers for bull fertility.

Comparison of in vitro fertilization and nuclear transfer techniques in the production of buffalo pre-implantation embryos

Abstract This study was conducted to evaluate the timing of cleavage and blastocoel formation of in vitro fertilized and nuclear transfer embryos and to compare the efficiency of in vitro fertilization (IVF) and somatic cell nuclear transfer (SCNT) techniques in the production of buffalo embryos under the same culture system. Cumulus oocyte complexes (COCs) were matured in vitro for 22 and 24 hr for SCNT and IVF, respectively. For IVF, COCs were inseminated with frozen-thawed semen and cultured in modified synthetic ovi-ductal fluid supplemented with amino acids for 7 days. For SCNT, ear skin fibroblasts were inserted individually into enucleated oocytes, fused electrically, and activated with ethanol followed by cycloheximide treatment for 6 hr before culture in the same condition as IVF embryos. The results showed that SCNT embryos cleaved and formed blastocoel earlier than IVF embryos. The cleavage rate is significantly higher in SCNT embryos; while the blastocyst formation rate of IVF embryos is significantly higher (P<0.01) than SCNT embryos. The shorter time taken from cleavage to blastocoel formation by NT embryos as compared to in vitro fertilized ones suggests a difference in their developmental kinetics. The difference in the developmental competence between NT and IVF embryos warrants further investigation.