The aim of this study was to compare the genetic variation of five local chicken breeds reared in Poland. Twenty-seven microsatellite markers were investigated in 138 birds belonging to five breeds: ...Miniature Cochin (MCO), Gold Italian (GI), Green Legged Partridge (GLP), Silver Italian (SI) and White Leghorn (WL). One hundred eighty five alleles were detected in the overall population, with a mean number of 6.85 ± 3.32 alleles per locus. For the local breeds, the observed and expected heterozygosity ranged from a minimum of 0.287 to a maximum of 0.458 and from 0.397 to 0.499 for the GI and SI breeds, respectively. The overall population heterozygote deficiency was 0.430, the average Wright’s inbreeding coefficient (FIS) was 0.061 and the heterozygote deficiency due to breed subdivision was 0.393. Wright’s fixation index was slightly positive for all breeds excluding MCO (FIS = -0.476) and the estimated molecular inbreeding (fij) within breed ranged from 0.296 (GLP and SI) to 0.361 (WL) evidencing limited coancestry. Mean allelic richness, obtained with rarefaction method based on sixteen observations, was 2.12 being the WL the less variable (1.79). Tomiuk and Loeschcke’s DTL genetic distance values were used to draw a neighbornet network which separated the cluster made of MCO and GLP from the cluster of GI, WL and SI. The results arising from our microsatellites analysis represent a starting point for the valorization of these local Polish chicken breeds for monitoring and preserving their genetic variability.
Abstract
Human parathyroid hormone‐related protein (PTHrP) is expressed in various tissues where it acts as an endocrine/paracrine factor involved in cellular growth, differentiation and development ...of fetal skeleton. As for parathyroid hormone (PTH), which is the hormone responsible for regulation of extracellular calcium homeostasis, the N‐terminal 1‐34 fragment can reproduce the full spectrum of calciotropic activities inherent in full‐length PTH. Truncation of six amino acid residues from the N‐terminus of both hormone sequences generates 7‐34 fragments which act as weak antagonists. Although PTH(7‐34) is a pure antagonist, PTHrP(7‐34) acts as partial agonist against the receptor shared by both hormones, the PTH/PTHrP receptor. In the current study, we analyzed the conformation of Leu
11
,
d
‐Trp
12
,Lys
26
,Asp
30
PTHrP(7‐34)NH
2
(
hybrid‐lactam
) in a 1:1 mixture of H
2
O/TFE‐
d
3
at pH 4 by circular dichroism, nuclear magnetic resonance and distance geometry calculations. This weak antagonist (
K
b
= 650 n
m
) combines two modifications: Leu
11
,
d
‐Trp
12
(
K
b
= 5.1 n
m
), reported to eliminate partial agonism and enhance potency, and Lys
26
‐Asp
30
lactamization (
K
b
=
31 n
m
), aimed to stabilize the helical structure of the principal binding domain attributed to residues 25‐34. The helical content in 30% trifluoroethanol is 88%, i.e., higher than the corresponding linear analog, and comprises the
d
‐Trp
12
‐Thr
33
segment. This hybrid lactam contains a rigid helical segment spanning the 14‐18 sequence followed by a hinge motif around Arg
19‐20
, but the sequence 14‐18 forms a stable helix. In all potent lactam‐containing, PTHrP‐derived agonists and antagonists studied so far, the dominant structural motif consists of two helical domains at the two ends of the sequence and of two hinge regions centered around Gly
12
‐Lys
13
and Arg
19
. The weakly active agonists and antagonists do not exhibit the “hinge” around position 19. These findings suggest that the presence and location of discrete hinge regions that connect the N‐ and C‐terminal helices are essential for generating the bioactive conformation of ligands for the PTH/ PTHrP receptor.
The authors compared the oxygen consumption in platelets from the umbilical cord blood of 36 healthy newborn infants with that of 27 adult subjects, before and after thrombin addition (1.67 U/ml). ...Oxygen consumption at rest was 6 mumol/10(9)/min in adult control platelets and 5.26 in newborn infants. The burst in oxygen consumption after thrombin addition was 26.30 mumol/10(9)/min in adults and 24.90 in infants. Dinitrophenol did not inhibit the burst of O2 consumption in platelets in 8 out of 10 newborn infants, while the same concentration caused a decrease in 9 out of 10 adult subjects. Deoxyglucose inhibited the burst in O2 consumption in newborn infant and adult platelets by about 50%. KCN at the concentration of 10(-4) M completely inhibited basal oxygen consumption but did not completely inhibit the burst after thrombin. At the concentration of 10(-3) M, it inhibited both basal O2 consumption and the burst in infants and adult subjects.
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