Genetic studies of water buffalo blood markers. I. Red cell acid phosphatase,albumin, catalase,red cell α-esterase-3, group-specific component,and protease inhibitor

We have developed the methodologies for typing and family studies to establish the modes of inheritance of water buffalo red cell acid phosphatase (Acp), protease inhibitor (Pi), and group-specific component (Gc) on isoelectric focusing and albumin (Alb), red cell -esterase-3 (Est-3), and catalase (Cat) on polyacrylamide gel electrophoresis. Family studies showed that Pi, Gc, Alb, and Cat are coded by autosomal genes with two codominant alleles, while Est-3 is autosomal with two codominant alleles and a recessive null allele and Acp exhibits three codominant alleles.This project was funded by the Australian Centre for International Agricultural Research through Grant PN 8364 and the Malaysian programme for Intensification of Research in Priority Areas through Grant IRPA 1-07-05-057.     

Relationship of scrotal circumference and testicular volume to age and body weight in the swamp buffalo (Bubalus bubalis)

Scrotal circumference (SC) and testicular volume (TV) were measured in 65 swamp buffalo bulls ranging in age from 7 to 60 months and weighing 130 kg to 560 kg. Ages and body weight (BW) were recorded for each male at the time of measurement to find out if they correlated with SC and TV. SC and TV increased linearly and correlated significantly with age and BW (SC vs age: r = 0.74, p<0.01; SC vs BW: r = 0.88, p<0.01; TV vs BW: r = 0.82, p<0.01). SC measurements ranged from 15.1 +/- 1.1 cm to 24.0 +/- 0.4 cm for ages ranging from 10.0 +/- 0.6 to 48.5 +/- 6.3 months, revealing that testicular size in swamp buffaloes was very much smaller than domestic cattle. The SC norms distributed with age would be useful in the evaluation of swamp buffalo males for breeding soundness.     

Isolation and Sequence Characterization of Mammary Derived Growth Inhibitor Gene of Riverine Buffalo (Bubalus Bubalis)

In this study, attempts have been made to identify and characterize water buffalo (Bubalus bubalis) mammary derived growth inhibitor (MDGI) gene, isolated from a mammary gland cDNA library of lactating buffalo. The complete MDGI cDNA was of 698 nucleotides, consisting 61 nucleotides in 5′ UTR, coding region of 402 nucleotides, and 235 nucleotides representing the 3′ UTR. Comparison of nucleotide and deduced amino acid sequence data with that of MDGI//fatty acid binding protein (FABP) of other species shows three buffalo specific nucleotide changes while seven nucleotide changes were common to cattle and buffalo. Buffalo and cattle MDGI had 100% amino acid sequence similarity, which also shared three amino acid changes: 34 (Ala-Gly), 109 (Leu-Met), and 132 (Glu-Gln) as compared to other species. Comparison with FABPs reported from other cattle tissues revealed highest amino acid sequence similarity with FABP-heart (100%) and least with FABP-liver (20.5%). Phylogenetic analysis revealed cattle MDGI to be closest to buffalo, while mouse MDGI was distantly placed, whereas different tissue derived FABPs of cattle showed FABP-heart closest and FABP-epidermis most distantly placed from buffalo MDGI. This report also differs from the earlier findings that MDGI is intermediate of FABP-heart and adipose.     

Identification of Novel Allelic Variants of Integrin Beta 2 (ITGB2) Gene and Screening for Bubaline Leukocyte Adhesion Deficiency Syndrome in Indian Water Buffaloes (Bubalus bubalis)

A fragment of 570 bp corresponding to exon 5 and 6 of integrin beta 2 (ITGB2) gene was amplified for screening D128G mutation in one hundred and fifty two buffaloes (Bubalus bubalis) which causes bovine leukocyte adhesion deficiency syndrome (BLAD) in cattle, as well as to ascertain polymorphism. TaqI PCR-RFLP revealed no such mutation thus indicating the absence of bubaline leukocyte adhesion deficiency (BuLAD) allele in animals under study. However, the polymorphism studies using MspI restriction enzyme revealed two genotypic patterns viz. AA pattern (bands of 293, 141, 105, and 31 bp) and BB pattern (bands of 293, 105, 77, 64, and 31 bp). The sequences of A and B alleles were submitted to the GenBank (EU853307 and AY821799).     

Mitochondrial DNA diversity patterns in Pakistani buffalo

The Indian subcontinent is considered to be the likely centre of river buffalo domestication, based on population dynamics, archaeological evidence and genetic diversity. Recent studies on mitochondrial DNA diversity have drawn useful conclusions about the domestication history of Bubalus bubalis. The conclusions of these studies are, however, incomplete, unless samples can also be analysed from Pakistan, which contains the second largest buffalo population of the world. Here, we report the results of the first study on mitochondrial D-loop sequence diversity in five breeds of Pakistani buffalo. Analysis of sequence variations in 503-bp of the D-loop region of 123 animals revealed 52 haplotypes, including 40 singletons. Multidimensional display of breed pairwise F(ST) values revealed no strong clustering of breeds. Bayesian, maximum parsimony, neighbour joining and UPGMA trees revealed a topology consistent with domestication as well as subsequent introgression of multiple maternal lineages from the wild stocks. Reduced median network analysis provided evidence of population expansion from more than one set of haplotypes. The study also confirmed that Pakistani buffalo are of the river type. The observed mitochondrial D-loop sequence diversity suggests that Pakistani areas bordering India might have contributed to the initiation of domestication of the present-day river buffalo.     

Strong and stable geographic differentiation of swamp buffalo maternal and paternal lineages indicates domestication in the China/Indochina border region

The swamp type of the Asian water buffalo is assumed to have been domesticated by about 4000 years BP, following the introduction of rice cultivation. Previous localizations of the domestication site were based on mitochondrial DNA (mtDNA) variation within China, accounting only for the maternal lineage. We carried out a comprehensive sampling of China, Taiwan, Vietnam, Laos, Thailand, Nepal and Bangladesh and sequenced the mtDNA Cytochrome b gene and control region and the Y‐chromosomal ZFY, SRY and DBY sequences. Swamp buffalo has a higher diversity of both maternal and paternal lineages than river buffalo, with also a remarkable contrast between a weak phylogeographic structure of river buffalo and a strong geographic differentiation of swamp buffalo. The highest diversity of the swamp buffalo maternal lineages was found in south China and north Indochina on both banks of the Mekong River, while the highest diversity in paternal lineages was in the China/Indochina border region. We propose that domestication in this region was later followed by introgressive capture of wild cows west of the Mekong. Migration to the north followed the Yangtze valley as well as a more eastern route, but also involved translocations of both cows and bulls over large distances with a minor influence of river buffaloes in recent decades. Bayesian analyses of various migration models also supported domestication in the China/Indochina border region. Coalescence analysis yielded consistent estimates for the expansion of the major swamp buffalo haplogroups with a credibility interval of 900 to 3900 years BP. The spatial differentiation of mtDNA and Y‐chromosomal haplotype distributions indicates a lack of gene flow between established populations that is unprecedented in livestock.     

Lactate dehydrogenase in two digenetic trematodes and their host

Polyacrylamide gel electrophoresis of the two digenetic trematodes, Gigantocotyle explanalum from the liver and Gastrothylax crumenifer from the rumen of the water buffalo, Bubalus bubalis revealed the presence of at least six and seven isoenzymes of lactate dehydrogenase (LDH), respectively in a partially purified enzyme preparation. The respective host tissues showed five isoenzymes of LDH, which are characteristic to the vertebrates. Both parachloromercuribenzoate and iodoacetate affected the LDH activity of the parasites and host tissues differently. Spectrophotometric analysis also showed different specific activity and susceptibility to the action of thiol inhibitors. The host LDH was quite stable at 57°C for 30 min, but that of the parasites was less stable.     

Nucleotide diversity of mitochondrial DNAs between the swamp and the river types of domestic water buffaloes,Bubalus bubalis,based on restriction endonuclease cleavage patterns

Cleavage patterns of mitochondrial DNAs (mtDNAs) by 15 restriction endonucleases were analyzed for 10 swamp and 13 river types of domestic water buffaloes. Digestions with nine enzymes exhibited polymorphisms giving two or three kinds of cleavage patterns. Five mtDNA types were identified, three types in the swamp buffaloes of the Philippines, Vietnam, and Indonesia (S-types) and two types in the river buffaloes of Bangladesh and Pakistan (R-types). Nucleotide diversities ranged from 0.2 to 0.6% within the S- and R-types and from 1.9 to 2.4% between the R-types and the S-types. These values indicated that R-type and S-type mtDNAs differentiated at thesubspecific level of other mammalianspecies reported. The possibility of polyphyletic domestication in different places is discussed for the origin of two distinct types of domestic water buffaloes.     

The Sertoli cell of the water buffalo (Bubalus bubalis) during the spermatogenic cycle

Summary Ultrastructural features and morphometric evaluations of buffalo Sertoli cells are reported for the six phases of the spermatogenic cycle. The phases of the tubular seminiferous epithelium are identified according to characteristic cellular associations with completed spermiation as demarcation between two cycles. Average tubular diameter (245 m) and epithelial height (61 m) do not vary significantly during the cycle. The relative Sertoli cell volume in the seminiferous epithelium varies between 30% (phase 4) and 39% (phase 8). The calculated volume of a single Sertoli cell increases from a nadir of 7118 m³ in phase 3 abruptly to a maximum of 8968 m³ in phase 4 and is then gradually reduced during the following phases. The Sertoli cell surface area shows a similar trend: it amounts to 11105 m² in phase 3 and to 14260 m² in phase 4. The contact area of the Sertoli cell with adjacent cells and structures is subject to characteristic changes; from the expansion of basal Sertoli-Sertoli contacts it is concluded that the blood-testis barrier in the buffalo is particularly tight during phases 8, 1 and 2. The irregularly contoured nucleus contains a vesicular nucleolus, has a calculated volume from 465 m³ to 543 m³ and occupies 5 to 7% of the cell. Volume percentages of mitochondria (4%), Golgi apparatus and lysosomal bodies are rather constant during the cycle. Whorls and orderly arranged aggregates of the smooth endoplasmic reticulum occur in basal location as well as in close association with elongating spermatids. Smooth ER is the organelle that exhibits the most prominent changes during the Sertoli cell cycle: it occupies 5.79% in phase 3 and 20.9% in phase 4 of the total cellular volume. Phagocytosis of residual bodies is insignificant in this species and a lipid cycle is absent in buffalo Sertoli cells.     

How many buffalo does it take to change a savanna? A response to Bowman et al. (2008)

Bowman et al. (Journal of Biogeography, 2008, 35 , 1976–1988) aimed to explain observed increases in woody cover on floodplains and savannas of Kakadu National Park using estimates of buffalo (Bubalus bubalis) density as a causal variable. They found that buffalo were a minor model variable and concluded that buffalo are ‘not a major driver of floodplain and eucalypt dynamics’. However, the authors mislabelled the historical density of buffalo on their site, citing a period as high density instead of low density. Further, their results were not contextualized within the substantial body of scientific and historical evidence of the buffalo’s strong influence on vegetation in Kakadu. The authors instead postulated three unanalysed drivers of observed patterns of change: fire regime, rainfall and atmospheric CO₂. We suggest that further analyses of change in woody vegetation should make use of accurate historical records of grazers as well as available data sets on fire history.