Effect of egg turning and incubation time on carbonic anhydrase gene expression in the blastoderm of the Japanese quail (Coturnix c. japonica)

1. The gene expression of carbonic anhydrase, a key enzyme for the production of sub-embryonic fluid (SEF), was assessed in turned and unturned eggs of the Japanese quail. The plasma membrane-associated isoforms CA IV, CA IX, CA XII, CA XIV, and the cytoplasmic isoform CA II, were investigated in the extra-embryonic tissue of the blastoderm and in embryonic blood. 2. Eggs were incubated at 37.6 degrees C, c.60% RH, and turned hourly (90 degrees ) or left unturned. From 48 to 96 h of incubation mRNA was extracted from blastoderm tissue, reverse-transcribed to cDNA and quantified by real-time qPCR using gene-specific primers. Blood collected at 96 h was processed identically. 3. Blastoderm CA IV gene expression increased with the period of incubation only in turned eggs, with maxima at 84 and 96 h of incubation. Only very low levels were found in blood. 4. Blastoderm CA II gene expression was greatest at 48 and 54 h of incubation, subsequently declining to much lower levels and unaffected by turning. Blood CA II gene expression was about 25-fold greater than in the blastoderm. 5. The expression of CA IX in the blastoderm was the highest of all isoforms, yet unaffected by turning. CA XII did not amplify and CA XIV was present at unquantifiable low levels. 6. It is concluded that only gene expression for CA IV is sensitive to egg turning, and that increased CA IV gene expression could account for the additional SEF mass found at 84 to 96 h of incubation in embryos of turned eggs.     

Movement of Road Salt to a Small New Hampshire Lake

Runoff of road salt from an interstate highway in New Hampshire has led to contamination of a lake and a stream that flows into the lake, in spite of the construction of a diversion berm to divert road salt runoff out of the lake drainage basin. Chloride concentration in the stream has increased by over an order of magnitude during the 23 yr since the highway was opened, and chloride concentration in the lake has tripled. Road salt moves to the lake primarily via the contaminated stream, which provides 53% of all the chloride to the lake and only 3% of the total streamflow to the lake. The stream receives discharge of salty water from leakage through the diversion berm. Uncontaminated ground water dilutes the stream downstream of the berm. However, reversals of gradient during summer months, likely caused by transpiration from deciduous trees, result in flow of contaminated stream water into the adjacent ground water along the lowest 40-m reach of the stream. This contaminated ground water then discharges into the lake along a 70-m-wide segment of lake shore. Road salt is pervasive in the bedrock between the highway and the lake, but was not detected at all of the wells in the glacial overburden. Of the 500 m of shoreline that could receive discharge of saly ground water directly from the highway, only a 50-m-long segment appears to be contaminated.     

Gestational Length and First Postpartum Ovulation of Criollo Mares on a Stud Farm in Southern Brazil

The Criollo horse industry requires more efforts toward a better understanding of breed characteristics and physiology; few studies have been conducted in Criollo horses to fulfill this demand. Toward this aim, 70 Criollo mares (between 3 and 28 years of age) underwent physiologic evaluation of the length of gestation, occurrence of foal heat, and interval to postpartum ovulation. Gestation length in the 70 mares was 335.6 ± 10.5 days, varying from 312 to 364 days. The mean (±SD) interval from parturition to first ovulation of 42 mares that foaled between September and December of 2005 and 2006 was 19.9 ± 14.0 days. Eighty-three percent of the mares had an interval to foal heat ovulation shorter than 20 days (35/42). The mean (±SD) parturition to ovulation interval of these mares was 14.2 ± 3.0 days.