指长比与乳腺癌的相关性研究

本文研究了宁夏汉族女性256例(正常对照:128例,乳腺癌患者:128例)左右手指长比(2D∶3D、2D∶4D、2D∶5D、3D∶4D、3D∶5D、4D∶5D),比较其均值的差异性;分析了指长比与年龄间的关系。结果表明:1)宁夏汉族正常女性与乳腺癌患者组指长比均值呈现2D∶3D<2D∶4D<3D∶4D<2D∶5D<4D∶5D<3D∶5D的趋势;2)乳腺癌患者组指长比均值均高于正常对照组,2D∶3D(P<0.05)、2D∶4D(P<0.01)、2D∶5D(左手P4D的比例高于对照组;3)乳腺癌患者组指长比均值与发病年龄呈高度负相关(P<0.001)。     

Genetic variation of new 21 autosomal short tandem repeat loci in a Chinese Salar ethnic group

In the present study, we reported the allele frequencies for new 21 autosomal short tandem repeat (STR) loci, including D6S474, D12ATA63, D22S1045, D10S1248, D1S1677, D11S4463, D1S1627, D3S4529, D2S441, D6S1017, D4S2408, D19S433, D17S1301, D1GATA113, D18S853, D20S482, D14S1434, D9S1122, D2S1776, D10S1435 and D5S2500 loci. Forensic statistical parameters were estimated from a sample set of 120 unrelated healthy individuals from the Salar ethnic group in Xunhua Salar Autonomous County of Qinghai province, China. A total of 151 alleles were observed at 21 STR loci in the population, and their allele frequencies were in the range of 0.004–0.554. All STR loci showed a high degree of genetic polymorphisms, and the combined probability of exclusion, combined power of discrimination and combined probability of matching for all 21 STR loci were 0.9999993134, 0.99999999999999999991739 and 8.2607 × 10⁻²⁰, respectively. For all the 21 STR loci in the Salar ethnic group, the observed genotypic data showed no significant deviation from those expected under the Hardy-Weinberg equilibrium. The allele frequency distributions for the 21 autosomal STR loci were compared between the Salar group and its neighboring populations and significant differences were detected among these populations at D1S1677, D2S441, D3S4529, D4S2408, D6S1017, D11S4463, D12ATA63, D14S14343, D18S853, D19S433 and D22S1045 loci.     

The 2nd:4th digit ratio,sexual dimorphism,population differences,and reproductive success: evidence for sexually antagonistic genes?

The ratio between the length of the 2nd and 4th digit (2D:4D) is sexually dimorphic, with mean male 2D:4D lower than mean female 2D:4D. It recently was suggested that 2D:4D is negatively correlated with prenatal testosterone and positively correlated with prenatal estrogen. It is argued that high prenatal testosterone and low estrogen (indicated by low 2D:4D) favors the male fetus and low prenatal testosterone and high estrogen (indicated by high 2D:4D) favors the female fetus. The patterns of expression of 2D:4D are interpreted in terms of sexually antagonistic genes.We report data on the following. (a) reproductive success and 2D:4D from England, Germany, Spain, Hungary (ethnic Hungarians and Gypsy subjects), Poland, and Jamaica (women only). Significant negative associations were found between 2D:4D in men and reproductive success in the English and Spanish samples and significant positive relationships between 2D:4D in women and reproductive success in the English, German, and Hungarian samples. The English sample also showed that married women had higher 2D:4D ratios than unmarried women, suggesting male choice for a correlate of high ratio in women, and that a female 2D:4D ratio greater than male 2D:4D predicted high reproductive success within couples. Comparison of 2D:4D ratios of 62 father:child pairs gave a significant positive relationship. This suggested that genes inherited from the father had some influence on the formation of the 2D:4D ratio. Waist:hip ratio in a sample of English and Jamaican women was negatively related to 2D:4D. (b) Sex and population differences in mean 2D:4D in samples from England, Germany, Spain, Hungary (including ethnic Hungarians and Gypsy subjects), Poland, Jamaica, Finland, and South Africa (a Zulu sample). Significant sex and population differences in mean 2D:4D were apparent.     

Revision of the 'nudidrosophila' and 'ateledrosophila' species groups of Hawaiian Drosophila (Diptera: Drosophilidae), with descriptions of twenty-two new species

Abstract.  The 'nudidrosophila' and 'ateledrosophila' species groups, formerly described as genera, are a relatively small and understudied part of the enormous Hawaiian Drosophila radiation. Only nine species were described previously. Here we revise the two groups, provide a key to males and females, and describe fully all species. The 'ateledrosophila' group now contains three species, D. diamphidia Hardy, D. papala sp.n. , and D. preapicula Hardy. The 28 species of the 'nudidrosophila' group are separated into five subgroups: 'hirtitibia' ( D. hirtitibia Hardy, D. konaensis sp.n. , D. mawaena sp.n. , and D. papaalai sp.n. ); 'kahania' ( D. kahania sp.n. and D. longipalpus sp.n. ); 'nudidrosophila' ( D. aenicta Hardy, D. amita Hardy, D. canavalia sp.n. , D. eximia Hardy, D. gemmula Hardy, D. kualapa sp.n. , D. lepidobregma Hardy, D. mahui sp.n. , D. malele sp.n. , D. panoanoa sp.n. , and D. poonia sp.n. ); 'okala' ( D. akoko sp.n. , D. kuhao sp.n. , D. makawao sp.n. , D. okala sp.n. , and D. panina sp.n. ); and 'velata' ( D. halapepe sp.n. , D. kauaiensis sp.n. , D. lauoho sp.n. , D. milolii sp.n. , D. pohaka sp.n. , and D. velata Hardy).     

End product inhibition of hepatic 25-hydroxyvitamin D production in the rat: specificity and kinetics

The role of vitamin D metabolites in the regulation of hepatic 25-hydroxyvitamin D production was investigated by examining the effects of 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D, and 24,25-dihydroxyvitamin D on the synthesis of [25-3H]hydroxyvitamin D by rachitic rat liver homogenates. Production of [25-3H]hydroxyvitamin D was inhibited by 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D, but not by 24,25-dihydroxyvitamin D. 25-Hydroxyvitamin D increased the Km of the vitamin D-25-hydroxylase enzyme(s), while 1,25-dihydroxyvitamin D decreased the Vmax with a Ki of 88.7 ng/ml. Inhibition of hepatic 25-hydroxyvitamin D production by 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D may be another control mechanism to regulate circulating vitamin D levels.     

1 alpha-hydroxylation of 24-hydroxyvitamin D2 represents a minor physiological pathway for the activation of vitamin D2 in mammals

C24-Hydroxylation was evaluated as a possible activation pathway for vitamin D2 and vitamin D3. Routine assays showed that 24-hydroxyvitamin D2 and 1,24-dihydroxyvitamin D2 could be detected in rats receiving physiological doses (100 IU/day) of vitamin D2; however, 24-hydroxyvitamin D3 could not be detected in rats receiving similar doses of vitamin D3. In rats, 24-hydroxyvitamin D2 was very similar to 25-hydroxyvitamin D2 at stimulating intestinal calcium transport and bone calcium resorption. The biological activity of 24-hydroxyvitamin D2 was eliminated by nephrectomy, suggesting that 24-hydroxyvitamin D2 must undergo 1 alpha-hydroxylation to be active at physiological doses. In vivo experiments suggested that when given individually to vitamin D deficient rats, 24-hydroxyvitamin D2, 25-hydroxyvitamin D2, and 25-hydroxyvitamin D3 were 1 alpha-hydroxylated with the same efficiency. However, when presented simultaneously, 24-hydroxyvitamin D2 was less efficiently 1 alpha-hydroxylated than either 25-hydroxyvitamin D3 or 25-hydroxyvitamin D2. 1,24-Dihydroxyvitamin D2 was also approximately 2-fold less competitive than either 1,25-dihydroxyvitamin D2 or 1,25-dihydroxyvitamin D3 for binding sites on the bovine thymus 1,25-dihydroxyvitamin D receptor. These results demonstrate that 24-hydroxylation followed by 1 alpha-hydroxylation of vitamin D2 represents a minor activation pathway for vitamin D2 but not vitamin D3.     

Dopamine D5 receptor agonist high affinity and constitutive activity profile conferred by carboxyl-terminal tail sequence

The mammalian dopamine D1-like receptor gene family is comprised of two members, termed D1/D1A and D5/D1B. In an attempt to define the role of the carboxyl terminal (CT) tail in the expression of D5 subtype-specific pharmacological and constitutive activity profiles, we examined a series of D5 receptor chimeras in which only the CT tail was swapped with corresponding sequences encoding human/vertebrate D1-like receptors. D5/D1(CT) or D5/D1D(CT) tail substitution mutants displayed a rank order of potency and agonist affinities virtually mimicking wild-type (wt) D1 receptors, as indexed by both ligand binding and dopamine-stimulated cAMP accumulation assays, and, similar to wt D1 receptors, did not exhibit receptor constitutive activity or responsiveness to inverse agonists. D1/D5(CT) or D1/D1D(CT) tail receptor mutants displayed agonist pharmacological and functional characteristics not significantly different from parental D1 or mutant D5/D1(CT) and D5/D1D(CT) receptors. The affinities for numerous antagonists remained essentially unchanged for all receptor chimeras relative to parental wt receptors. A series of stepwise D5-CT-tail truncation/deletion mutants identified the region encoded by amino acids 438-448 and particularly Gln(439), as necessary and sufficient for the full expression of high affinity agonist and functional D5 receptor characteristics. Site-directed mutagenesis of the highly conserved D5/D1B receptor residue Gln(439)-(Ala/Ile), converts the full-length D5 receptor to one displaying "super" D5 characteristics with expressed affinities for discriminating agonists approximately 4- to 5-fold higher than wt D5 but without any concomitant increases of agonist-independent basal cAMP accumulation or intrinsic activity. Taken together, these data suggest that, in addition to other well characterized receptor domains, the agonist pharmacological and functional signature of the D5/D1B receptor is modulated by sequence-specific motifs within the CT tail and that one conserved amino acid in this region can further regulate D5 agonist high affinity binding interactions independent of receptor constitutive activity.     

Radiation of the genus Dysdera (Araneae, Haplogynae, Dysderidae) in the Canary Islands: The island of Gran Canaria

This study continues studies on the taxonomy and distribution of Dysdera in the Canarian archipelago. Four new species are described: Dysdera andamanae sp. n., D. arabisenen sp. n., D. tibicena sp. n. and D. yguanirae sp. n. Four new synonymies are reported: D. bailadero Wunderlich, 1991 and D. pauciserae Wunderlich, 1991 = Dysdera iguanensis Wunderlich, 1987, D. tamadabaensis Wunderlich, 1991 = D. paucispinosa Wunderlich, 1991; D. sinuosa Wunderlich, 1994 = D. tilosensis Wunderlich, 1991. Six species are redescribed: D. bandamae Schmidt, 1973, D. iguanensis Wunderlich, 1987, D. insulana Simon, 1883, D. paucispinosa Wunderlich, 1991, D. tilosensis Wunderlich, 1991 and D. verneaui Simon, 1883; and neotypes are designated for D. insulana and D. verneaui . The presence of the following species in Gran Canaria is reported for the first time: D. iguanensis , formerly only collected on Tenerife, D. insulana , previously of doubtful location, and D. levipes , known from Tenenfe and La Gomera. Morphological affinities, ecology and distribution of the species are discussed.     

Nuclear ribosomal DNA sequence variation and evolution of spotted marsh-orchids (Dactylorhiza maculata group)

Sequences of both internal and external transcribed spacers of nuclear ribosomal DNA were sequenced for four species belonging to the Dactylorhiza maculata group or "spotted marsh-Orchids". These four species are D. fuchsii, D. saccifera, D. foliosa, and D. maculata. Extensive nuclear ribosomal DNA polymorphism was uncovered within the diploid D. fuchsii and the putative autotetraploid D. maculata. Within the phylogenetic trees reconstructed using parsimony and Bayesian analyses, four main lineages (A, B, C, and D) were well supported. While D. saccifera, D. maculata, and D. foliosa were confined to clades B, C, and D, respectively, D. fuchsii accessions were spread over three clades (A, B, and C). Lineage C, which included accessions of the diploid D. fuchsii and the tetraploid D. maculata, was closely related to the lineage of D. foliosa (lineage D), an endemic diploid species from Madeira. Moreover, intra-individual polymorphism was found within accessions of D. maculata, D. fuchsii, and D. saccifera. It is shown that in some instances two lineages, contributed to the observed intra-individual polymorphism (C and A in D. maculata, A and B in D. fuchsii and D. saccifera). Evolutionary scenarios leading to this extensive nuclear ribosomal DNA polymorphism are discussed in the light of results from maternally inherited chloroplast DNA markers and an autopolyploid origin of D. maculata from a D. foliosa-like ancestor is postulated.     

Sequence-based identification of species belonging to the genus Debaryomyces

In the present study we assessed the identification by sequence analysis of the 15 species belonging to the genus Debaryomyces. We found that the following species can be identified both quickly and correctly by direct sequence comparison of the ribosomal 5.8S-ITS region: D. carsonii, D. etchelsii, D. maramus, D. melissophilus, D. occidentalis and D. yamadae. In contrast, the species D. castellii, D. coudertii, D. hansenii, D. nepalensis, D. polymorphus, D. pseudopolymorphus, D. robertsiae, D. udenii and D. vanrijiae showed high sequence similarity in ribosomal regions with one or several species. In these cases, sequence comparison of the ACT1 gene is proposed to ensure unequivocal strain designation.     

Potent activation of dopamine D3/D2 heterodimers by the antiparkinsonian agents, S32504, pramipexole and ropinirole

Recombinant, human dopamine D3 and D2 receptors form functional heterodimers upon co-expression in COS-7 cells. Herein, actions of the antiparkinsonian agents, S32504, ropinirole and pramipexole, at D3/D2L heterodimers were compared to their effects at the respective monomers and at split, chimeric D3trunk/D2tail and D2trunk/D3tail receptors: the trunk incorporated transmembrane domains (TDs) I-V and the tail TDs VI and VII. In binding assays with the antagonist [3H]nemonapride, all agonists were potent ligands of D3 receptors showing, respectively, 100-, 18- and 56-fold lower affinity at D2L receptors, mimicking the selective D3 receptor antagonist, S33084 (100-fold). At D3trunk/D2tail receptors, except for ropinirole, all drugs showed lower affinities than at D3 sites, whereas for D2trunk/D3tail receptors, affinities of all drugs were higher than at D2L sites. The proportion of high affinity binding sites recognized by S32504, pramipexole and ropinirole in membranes derived from cells co-expressing D3 and D2L sites was higher than in an equivalent mixture of membranes from cells expressing D3 or D2L sites, consistent with the promotion of heterodimer formation. In contrast, the percentage of high and low affinity sites (biphasic isotherms) recognized by S33084 was identical. Functional actions were determined by co-transfection of a chimeric adenylyl cyclase (AC)-V/VI insensitive to D3 receptors. Accordingly, D3 receptor-transfected cells were irresponsive whereas, in D2L receptor-transfected cells, agonists suppressed forskolin-stimulated cAMP production with modest potencies. In cells co-transfected with D3 and D2L receptors, S32504, ropinirole and pramipexole potently suppressed AC-V/VI with EC50s 33-, 19- and 11-fold lower than at D2L receptors, respectively. S32504 also suppressed AC-V/VI activity at split D3trunk/D2tail and D2trunk/D3tail chimeras transfected into COS-7 cells. In conclusion, antiparkinson agents behave as potent agonists at D3/D2'heterodimers', though any role in their actions in vivo remains to be demonstrated.     

Evidence for assortative mating on digit ratio (2D:4D), a biomarker for prenatal androgen exposure

The second-to-fourth digit ratio (2D:4D) presents an anatomical sex difference in humans. On average, men tend to have lower 2D:4D compared with women. There is fairly strong evidence for a role of the 2D:4D ratio as a biomarker for the organizational (permanent) effects of prenatal testosterone on the brain and behaviour. Recently, an accumulating research programme has shown 2D:4D to be related to a multitude of sex-dependent, hormonally influenced biosocial traits and phenotypes which reach into the domains of ability, behaviour, fertility, health, personality and sexuality. This study investigated the degree of assortative mating (spousal similarity) in a sample of 239 native Austrian couples of parental or grandparental age, all of them having reproduced. Results included: (i) significant spousal correlations of +0.19 and +0.18 for right-hand and left-hand 2D:4D, respectively, and +0.24 for average 2D:4D; (ii) no assortative mating effect on the right-minus-left difference in 2D:4D; (iii) indications consistent with a possible generational decrease of spousal similarity in 2D:4D; (iv) a prevalence of couples with a lower right-hand 2D:4D observed in the husband compared with his wife; and (v) relations of spousal 2D:4D patterns to spousal age differences, such that matings of men with more male-typical trait expressions (namely, a generally low right-hand 2D:4D or showing a lower right-minus-left 2D:4D difference than their wives) implicated larger male-minus-female age differences, i.e. younger wives. It is argued that assortative mating on 2D:4D operates indirectly and may be mediated through the assortment on other, more perceptible, physical traits and psychological phenotypes that entertain associations with 2D:4D and are relevant for courtship and mate choice.     

The Phylogenetic Relationships of the Members of the DROSOPHILA ROBUSTA Group

The phylogenetic relationships among the species of the D. robusta group were investigated by the analysis of chromosomal differences. Six of the ten known members of the D. robusta group were available for the study: D. colorata and D. robusta from the United States, and D. sordidula, D. pseudosordidula, D. lacertosa, and D. moriwakii from Japan. Analysis of the metaphase chromosomes from larval ganglion cells suggests that D. moriwakii and D. colorata, with rod-shaped X-chromosomes, are the more ancestral species, while D. sordidula, D. pseudosordidula, D. robusta, and D. lacertosa, with V-shaped X-chromosomes, are derived. The ancestral position of D. colorata and D. moriwakii is further strengthened by the fact that these are the two species in the D. robusta group that are cytologically closest to D. nigromelanica of the related D. melanica group. Of the four derived species, D. sordidula was found to be the closest to the ancestral species. The phylogeny based on the analysis of the gene sequences in the homologous chromosomes agreed with that indicated by the metaphase chromosomes. Since all attempts to obtain hybrids were unsuccessful except for the cross involving D. moriwakii females and D. colorata males, photographic maps of the salivary chromosomes were used to determine homology between the chromosomes of the different species. Evidence is presented to indicate that the D. robusta group originated in Asia (Japan), and that there were two migrations to the New World, the first leading to D. robusta, and the second to D. colorata. It is suggested that the route of migrations was across the Bering Land Bridge, and further, that the migrations occurred during the period from late Oligocene to middle Miocene, 20-25 million years ago.     

Seasonal life cycles and resource uses of flower- and fruit-feeding drosophilid flies (Diptera: Drosophilidae) in central Japan

Seasonal life cycles and resource uses of flower- and fruit-feeding drosophilids (Diptera: Drosophilidae) were studied from low to high altitudes in central Japan to understand their adaptation to seasonal changes of environmental conditions. Drosophila unipectinata and D. oshimai specialized to flowers, D. suzukii and D. subpulchrella depended almost on fruits, while D. lutescens , D. rufa , D. auraria , D. biauraria and D. sternopleuralis used both of them. It was assumed that D. unipectinata moved from low to high altitudes in June while D. oshimai , D. suzukii and D. subpulchrella in July. Migration of D. unipectinata is considered as a means to avoid summer heat or exploit early-summer resources at high altitudes. On the other hand, D. oshimai , D. suzukii and D. subpulchrella have the capacity to pass the summer at low altitudes, and therefore their migration is assumed as a means to escape from resource-poor conditions in summer at low altitudes or exploit resources at high altitudes. The generalist species, D. lutescens , D. rufa , D. auraria , D. biauraria and D. sternopleuralis , would not perform such extensive movements between low and high altitudes. They may pass the summer at low or mid altitudes depending on accidentally fallen immature fruits and/or some other resources such as decayed leaves.     

Genetic data provided by 21 autosomal STR loci from Chinese Tujia ethnic group

The aim of this study was to investigate allelic frequency distribution and forensic genetic parameters of autosomal short tandem repeats (STR) loci of the population samples from 107 Tujia individuals from Chinese Hubei Province. Twenty-one autosomal STR genetic markers (D9S1122, D6S474, D6S1017, D5S2500, D4S2408, D3S4529, D2S441, D2S1776, D22S1045, D20S482, D1S1677, D1S1627, D1GATA113, D19S433, D18S853, D17S1301, D11S4463, D12ATA63, D10S1248, D10S1435 and D14S1434) were simultaneously amplified in a new multiplex polymerase chain reaction system. 155 alleles for all the STR loci from the Tujia population were observed and the corresponding allelic frequencies ranged from 0.005 to 0.589. Expected heterozygosity, polymorphic information content, power of discrimination and power of exclusion of the 21 STR loci in the Tujia population were from 0.579 to 0.824, from 0.525 to 0.802, from 0.773 to 0.945 and from 0.257 to 0.641, respectively. Our results indicate that the autosomal STRs multiplex system provides highly informative STR data and could be useful in forensic individual identification and parentage testing in this region.     

The relationships among the species of the Drosophila virilis group inferred from the gene Ras1 sequences

Comparative analysis of a group of closely related Drosophila species (D. virilis, D. lummei, D. novamexicana, D. americana texana, D. flavomontana, D. montana, D. borealis, D. lacicola, D. littoralis, D. kanekoi, and D. ezoana) was conducted based on an incomplete sequence of gene Ras1. The pattern of the relationships among the species corresponded to that expected from analysis of morphological and cytogenetic characters. Statistical data favoring neutrality of the substitutions examined in the Ras1 gene are presented. This character of the gene Ras1 evolution confers more reliability to reconstruction of phylogenetic relationships among closely related species. The resultant tree for main phylads of the group is as follows: (D. virilis, D. lummei, D. montana, D. ezoana).     

Functional and autoradiographic characterization of dopamine D2-like receptors in the guinea pig heart

Dopamine receptors include the D1- (D1 and D5 subtypes) and D2-like (D2, D3, and D4 subtypes) families. D1-like receptors are positively and D2-like receptors negatively coupled to the adenylyl cyclase. Dopamine D2-like (D4 subtype) receptors have been identified in human and rat hearts. However the presence of D2 and D3 receptor subtypes is unclear. Furthermore, their role in cardiac functions is unknown. By autoradiographic studies of guinea pig hearts, we identified D3 and D4 receptors, using the selective radioligands [3H]-7-OH-DPAT and [3H]emonapride (YM-09151-2 plus raclopride). Western blot analysis confirmed D3 and D4 receptors in the right and left ventricle of the same species. Selective agonists of D3 and D4 receptors (+/-)-7-OH-DPAT and PD 168 077 (10(-9) to 10(-5) M, respectively) induced a significant negative chronotropic and inotropic effect in the isolated guinea pig heart preparation. Negative inotropic effect induced by PD 168 077 was associated with an inhibition in cyclase activity. No changes in cyclase activity were found with (+/-)-7-OH-DPAT. The aim of this study is to support the presence of D3 and D4 receptors in the heart. Although our results suggest that D3 and D4 receptors are functionally active in the heart, we need additional information with an antagonist and an agonist of improved potency and selectivity to understand the respective roles of D3 and D4 receptors in the cardiac functions.     

Unaltered D1, D2, D4, and D5 dopamine receptor mRNA expression and distribution in the spinal cord of the D3 receptor knockout mouse

Dopamine (DA) acts through five receptor subtypes (D1–D5). We compared expression levels and distribution patterns of all DA mRNA receptors in the spinal cord of wild-type (WT) and loss of function D3 receptor knockout (D3KO) animals. D3 mRNA expression was increased in D3KO, but no D3 receptor protein was associated with cell membranes, supporting the previously reported lack of function. In contrast, mRNA expression levels and distribution patterns of D1, D2, D4, and D5 receptors were similar between WT and D3KO animals. We conclude that D3KO spinal neurons do not compensate for the loss of function of the D3 receptor with changes in the other DA receptor subtypes. This supports use of D3KO animals as a model to provide insight into D3 receptor dysfunction in the spinal cord.     

Plasticity in D1-like receptor expression is associated with different components of cognitive processes

Dopamine D1-like receptors consist of D1 (D1A) and D5 (D1B) receptors and play a key role in working memory. However, their possibly differential contribution to working memory is unclear. We combined a working memory training protocol with a stepwise increase of cognitive subcomponents and real-time RT-PCR analysis of dopamine receptor expression in pigeons to identify molecular changes that accompany training of isolated cognitive subfunctions. In birds, the D1-like receptor family is extended and consists of the D1A, D1B, and D1D receptors. Our data show that D1B receptor plasticity follows a training that includes active mental maintenance of information, whereas D1A and D1D receptor plasticity in addition accompanies learning of stimulus-response associations. Plasticity of D1-like receptors plays no role for processes like response selection and stimulus discrimination. None of the tasks altered D2 receptor expression. Our study shows that different cognitive components of working memory training have distinguishable effects on D1-like receptor expression.     

A quantitative histological study of adrenal development during late gestation and the perinatal period in intact and hypophysectomized fetal sheep

Growth of the sheep adrenal was studied during late gestation and the perinatal period. Adrenals were recovered from 28 fetuses taken at D100 (D0: day of mating), D120, D132 and D144, and in 4 newborn animals 3 days after birth (equivalent to D151). Animals were of the Ile de France breed. Cortex (without capsule) and medulla volumes increased respectively by 7.2 and 2.4 between D100 and D151. The 2 parts had the same volume between D100 and D120; thereafter the cortex became predominant, representing 74% of the whole gland at D151. Hypertrophy and hyperplasia were shown after D132 in the cortex (zona fasciculata); they were observed later after D144 in the medulla (central zone). Fifteen fetuses hypophysectomized at D100 or D120 were recovered at D120 or D144. The lack of pituitary inhibited cortical growth (zona fasciculata) and suppressed hypertrophy and hyperplasia. The medulla continued to grow after hypophysectomy but to a lesser extent than in controls.