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D Pomp

Publications and source records attributed to D Pomp.

At least 37 records · Page 2Linked to original sources
PubMed1999

Quantitative genetics of energy balance--lessons from animal models.

Evidence for quantitative genetic variation in components of energy balance in animals is overwhelming. Much of this evidence is drawn from livestock species and relevant rodent models, especially long-term selection lines. This mini-review summarizes findings from several animal studies that have characterized quantitative genetic variation in energy intake and energy expenditure. Applications of this information toward understanding and treatment of human obesity are explored.

Animals↗
PubMed1999

Comparative mapping of 18 equine type I genes assigned by somatic cell hybrid analysis.

Polymerase chain reaction primers designed from horse cDNA sequences and from consensus sequences highly conserved in mammalian species were used to amplify markers for synteny mapping 18 equine type I genes. These markers were used to screen a horse-mouse somatic cell hybrid panel (UCDavis SCH). Fourteen primer sets amplified horse-specific fragments, while restriction enzyme digests of PCR products were used to distinguish the fragments amplified from horse and mouse with four primer sets. Synteny assignments were made based on correlation values between each marker tested and other markers in the UCDavis SCH panel database. The 18 horse genes were assigned to previously established synteny groups. Synteny mapping of two genes previously mapped in the horse by FISH was used to anchor two UCD synteny groups to horse chromosomes. Previous chromosome assignments of three equine loci by FISH were confirmed. Comparative mapping analysis based on published human-horse Zoo-FISH data and the synteny mapping of 14 horse genes confirmed the physical assignment of 12 synteny groups to the respective horse chromosomes and was used to infer the physical location of one synteny group.

Animals↗
PubMed1999

Identification of quantitative trait loci influencing traits related to energy balance in selection and inbred lines of mice.

Energy balance is a complex trait with relevance to the study of human obesity and maintenance energy requirements of livestock. The objective of this study was to identify, using unique mouse models, quantitative trait loci (QTL) influencing traits that contribute to variation in energy balance. Two F2 resource populations were created from lines of mice differing in heat loss measured by direct calorimetry as an indicator of energy expenditure. The HB F2 resource population originated from a cross between a noninbred line selected for high heat loss and an inbred line with low heat loss. Evidence for significant QTL influencing heat loss was found on chromosomes 1, 2, 3, and 7. Significant QTL influencing body weight and percentage gonadal fat, brown fat, liver, and heart were also identified. The LH F2 resource population originated from noninbred lines of mice that had undergone divergent selection for heat loss. Chromosomes 1 and 3 were evaluated. The QTL for heat loss identified on chromosome 1 in the HB population was confirmed in the LH population, although the effect was smaller. The presence of a QTL influencing 6-wk weight was also confirmed. Suggestive evidence for additional QTL influencing heat loss, percentage subcutaneous fat, and percentage heart was found for chromosome 1.

Adipose Tissue↗
PubMed1998

Report of the first workshop on the genetic map of bovine chromosome 1.

A report of the first workshop on the genetic map of bovine chromosome 1 (BTA1) is presented. Five laboratories contributed 31,962 informative meioses from 70 loci. Thirty-two loci which had been typed by at least two laboratories were used to construct a framework genetic map with a likelihood ratio support of at least 1000:1 for locus order. The resulting sex-averaged framework map contained 26 loci and spanned 163.6 CM. The lengths of the female and male maps were 159.5 CM and 165.3 CM, respectively, and there was evidence for an expansion in the telomeric one-third of the male map. Of the four cases where order for closely linked loci differed among the maps produced for each of the contributing laboratories, a consensus order was obtained for three in the framework map. The average genetic distance between framework loci on the sex-averaged map was 6.3 CM.

Animals↗
PubMed1998

Expression of an inter-alpha-trypsin inhibitor heavy chain-like protein in the pig endometrium during the oestrous cycle and early pregnancy.

In pigs, changes in an unidentified endometrial glycoprotein, pGP30, are temporally associated with rapid trophoblast elongation and initial placental attachment on day 12 of gestation. Identification of endometrial pGP30 was undertaken through protein purification, NH2-terminal amino acid sequencing and cDNA sequencing of products generated through reverse transcription-polymerase chain reaction. Sequencing of 35 amino acids from the NH2-terminal end of pGP30 revealed that the 30 kDa glycoprotein is a cleavage product from the C-terminal region of inter-alpha-trypsin inhibitor heavy chain 4 (I alpha IH4), previously known as inter-alpha-trypsin inhibitor heavy chain-like protein. I alpha IH4 is unique compared with the three other inter-alpha-trypsin inhibitor heavy chains as it does not contain a binding site for bikunin that has serine protease inhibitory activity and is sensitive to cleavage by kallikrein. Endometrial gene expression of I alpha IH4 was detected during the oestrous cycle (days 0-18) and early pregnancy (days 10-18). Gene expression of I alpha IH4 appeared to be enhanced during the midluteal phase (days 12 and 15) of the oestrous cycle and the period of trophoblast attachment (days 12-18). Expression of I alpha IH4 was not detected in day 12 conceptus tissue mRNA. Endometrial expression of I alpha IH4 in pigs may function as an acute phase protein for protection of the uterus from the inflammatory response induced by conceptus attachment to the uterine epithelium.

Amino Acid Sequence↗
PubMed1997

Variability in metabolic rate, feed intake and fatness among selection and inbred lines of mice.

Mouse populations differing in metabolic rate have been developed through selection for high (MH) and low (ML) heat loss (HLOSS), along with randomly selected controls (MC). Objectives of this study were to (a) compare MH, ML and MC lines for HLOSS and correlated traits of feed intake, body composition and organ weights; (b) compare three widely used inbred mouse lines with MH, ML and MC for the same traits; and (c) investigate potential genotype by diet interaction resulting from feeding diets differing in fat percentage. Heat loss (kcal/day) of MH and ML mice differed by 37% of the mean and remained significant (33%) when HLOSS was expressed on a fat-free mass basis. MH mice consumed more energy than ML with a greater difference in mice fed high-fat compared with standard diets (27% vs 13.9%). Despite greater energy consumption, MH mice were leaner than ML with a difference in total body fat percentage of 40%. The greatest difference in HLOSS between selection and inbred lines was between MH and C57BL/6J (BL), which differed by 26.3%. MH and BL mice also differed in energy intake (15.5%). Body composition of BL mice was similar to MH when fed a standard diet, but similar to ML when fed a high-fat diet. Crosses between MH and ML or between MH and BL would be useful to investigate the genetic regulation of, and identify quantitative trait loci influencing HLOSS, energy intake and body composition. Feeding of a high-fat diet may allow diet-specific loci influencing body composition to be identified in MH and BL lines.

Adipose Tissue, Brown↗
PubMed1997

Genetic dissection of obesity in polygenic animal models.

In contrast to diseases caused by single-gene defects, many of the most common human maladies such as obesity, atherosclerosis, diabetes, and hypertension exhibit continuous phenotypic variation and a predominantly multifactorial and polygenic basis. Genes with roles in energy balance, nutrient partitioning, lipid and insulin metabolism, and a variety of behavioral traits are likely interacting with environmental stimuli to regulate obesity phenotypes. With the current proliferation of highly polymorphic genetic markers and the refinement of experimental approaches, it is now possible to screen thoroughly the genomes of model organisms for the individual genes or quantitative trait loci (QTL) that control measurable polygenic traits such as obesity. With the growing wealth of comparative mapping, it will be possible to predict the location of a homologous locus in the human after first mapping it in the mouse. Many experiments have been conducted in mice, rats, and pigs to estimate the number, location, and effect of QTL controlling obesity and related traits. This review describes the design and strategies of such studies and summarizes the results and their implications toward understanding the complex nature of obesity in humans.

Animals↗
PubMed1997

Detection of transcripts for retinoic acid receptors, retinol-binding protein, and transforming growth factors during rapid trophoblastic elongation in the porcine conceptus.

Early conceptus development (Days 10-12) in the pig is characterized by rapid remodeling and elongation of the trophoblastic membrane. Endometrial synthesis and secretion of retinol-binding protein (RBP; transporter of retinol) into the uterine lumen parallels the rapid morphological transformation of the conceptus. Hence, retinoic acid, a powerful morphogen, may serve a critical function in trophoblastic remodeling and conceptus elongation through the various isoforms of retinoic acid receptor (RAR). We hypothesize that various transcripts for RAR will be expressed, possibly differentially, in the early developing porcine conceptus on Days 10-12 of gestation. Conceptuses were collected from pregnant gilts and individually frozen in liquid nitrogen after classification for morphological size. A total of 36 conceptuses (4 groups of 9) representing spherical (2-9 mm), early tubular (10-12 mm), late tubular (13-60 mm), and filamentous (> 100 mm) morphologies were assembled for qualitative assessment of mRNA for RAR alpha, RARbeta, RARgamma, RBP, and transforming growth factor beta (TGFbeta)-2 and -3 with reverse transcription polymerase chain reaction (RT-PCR). RBP gene expression was affected by stage of conceptus development (p < 0.05) as RBP expression increased in a linear fashion from 2-mm to 8-mm spherical conceptuses, decreased slightly in the tubular stage, and increased dramatically in filamentous conceptuses. RAR alpha, RARbeta, and RARgamma gene expression was evident at all stages of conceptus development. RAR alpha gene expression increased (p < 0.05) in a linear fashion from 2- to 8-mm spherical conceptuses, and expression plateaued in the 9- to 12-mm conceptuses. Expression of RAR alpha declined slightly at the tubular stage but dramatically increased in filamentous conceptuses. RARbeta gene expression was present across all stages of conceptus development although in diminutive amounts. RARgamma gene expression was evident in all stages of conceptus development but was not affected (p > 0.05) by developmental stage. Gene expression for TGFbeta-2 was not detected by RT-PCR at any stage of conceptus development, whereas TGFbeta-3 expression increased (p < 0.05) from the 2- to 8-mm conceptuses and remained high throughout trophoblastic elongation into the filamentous stage. The presence of mRNA for the RAR alpha, RARbeta, and RARgamma in elongating porcine conceptus provides evidence that RAR, particularly RAR alpha, may function as an important acceptor for retinoic acid and possibly regulate gene expression prior to and during rapid trophoblastic elongation in the porcine conceptus.

Actins↗