Effects of luminal pH and luminal HCO3 on CI-HCO3 exchange across turtle urinary bladder

The Cl-HCO3 exchange rate across turtle urinary bladder was studied by measuring the net flux of 36Cl in paired tissues. Serosal bicarbonate concentration and pH were held constant (10 mM and 7.6, respectively) while luminal composition was altered. The rate of net chloride absorption was the same at a luminal pH of 5 or 7 and at luminal HCO-3 concentrations of 0 and 10 mM. These results indicate that the affinity of the exchanger for luminal Cl- is much higher than that for luminal HCO-3 or OH-. Vanadate, an inhibitor of a number of ATPases, had no significant effect on chloride absorption.     

First International Workshop on Porcine Chromosome 6

Recent advances in the use of microsatellite markers and the development of comparative gene mapping techniques have made the construction of high resolution genetic maps of livestock species possible. Framework and comprehensive genetic linkage maps of porcine chromosome 6 have resulted from the first international effort to integrate genetic maps from multiple laboratories. Eleven highly polymorphic genetic markers were exchanged and mapped by four independent laboratories on a total of 583 animals derived from four reference populations. The chromosome 6 framework map consists of 10 markers ordered with high local support. The average marker interval of the framework map is 15.1 cM (sex averaged). The framework map is 135, 175 and 109 cM in length (for sex averaged, female and male maps, respectively). The comprehensive map includes a total of 48 type I and type II markers with a sex averaged interval of 3.5 cM and is 166, 196 and 126 cM (for sex averaged, female and male maps, respectively). Additional markers within framework map marker intervals can thus be selected from the comprehensive map for further analysis of quantitive trait loci (QTL) located on chromosome 6. The resulting maps of swine chromosome 6 provide a valuable tool for analysing and locating QTL.