Hydrogen cyanide and phenylthiocarbamide sensitivity, mid-phalangeal hair and color blindness in Yucatán, Mexico

Approximately 1450 persons, 800 of them unrelated, of both sexes from age eigth upward from the town of Ticul, Yucatán, Mexico, formed an American Indian (Maya) sample with apparently little Caucasian admixture for four genetic tests: ability to taste PTC and smell HCN, presence of mid-phalangeal hair, and color blindness. A modified PTC sorting test indicated a nontaster allele (t) frequency of 0.29 in Ticul, a relatively high result for American Indians but compatible with previously reported Mayan data. A color vision deficiency frequency of 3.6% was found in the total male sample, and a subsample of unrelated males had a rate of 2.8%. No color blind females were detected. The Ticuleños exhibited a high rate of midphalangeal hairlessness, characteristic of American Indians, with a notable sex differential: 75.9% for males, 87.1% for females. Previous studies of the inability to smell HCN, most of which suggest an X-linked recessive inheritance with an allele frequency of about 0.2, are reviewed. The Yucatán material, with a nonsmeller prevalence around 50% and no significant difference between the sexes, contradicts the X-linked recessive hypothesis on the basis of both population and family analyses. No simple Mendelian scheme appears to fit the Ticul HCN sensitivity test results.     

Autosomal recessive lethal mutations in two mutator stocks of Drosophila ananassae.

The frequency of recessive lethals in the 2nd chromosome was examined in two mutator stocks of Drosophila ananassae, ca and ca; px. They are characterized respectively by possessing an extrachromosomal clastogenic mutator in males, and by the retrotransposon "tom", which induces Om mutability only in females. The frequencies of recessive lethal mutations in the 2nd chromosome among progenies from males and females of the ca; px stock are 0.35 and 0.34 percent, respectively. Similarity of these frequencies indicates that tom does not induce recessive lethals in females. In contrast to the ca; px stock, the frequency of recessive lethals in males of the ca mutator stock was estimated to be 1.54 percent for the 2nd chromosome. No visible mutants except Minutes were recovered. Some recessive lethals derived from ca stock males were associated with chromosomal rearrangements. Being consistent with its high rate of Minute mutation it was demonstrated that the ca clastogenic mutator also induced recessive lethals.     

Iris pigmentation as a quantitative trait: variation in populations of European,East Asian and South Asian ancestry and association with candidate gene polymorphisms

In this study, we present a new quantitative method to measure iris colour based on high‐resolution photographs. We applied this method to analyse iris colour variation in a sample of individuals of East Asian, European and South Asian ancestry. We show that measuring iris colour using the coordinates of the CIELAB colour space uncovers a significant amount of variation that is not captured using conventional categorical classifications, such as ‘brown’, ‘blue’ or ‘green’. We tested the association of a selected panel of polymorphisms with iris colour in each population group. Six markers showed significant associations with iris colour in the European sample, three in the South Asian sample and two in the East Asian sample. We also observed that the marker HERC2 rs12913832, which is the main determinant of ‘blue’ versus ‘brown’ iris colour in European populations, is also significantly associated with central heterochromia in the European sample.     

Sexual size dimorphism, growth and maturity of the Japanese fluvial sculpin,Cottus pollux (large egg type), in the Inabe River, Mie prefecture, central Japan

The population structure of the Japanese fluvial sculpin,Cottus pollux (large egg type), in the upper reaches of the Inabe River, Mie Prefecture, central Japan, was investigated by a mark-and-recapture method from July 1989 to January 1991. Breeding of the species occurred from mid February to early May, peaking from mid February to late March. The mean size of mature males observed in March 1990 was significantly larger than that of females, showing apparent sexual size dimorphism. Data analysis of the growth of 1658 marked individuals revealed that the species matured at 2 years of age in both sexes. Whereas 1 year old males reached ca. 50–70 mm SL, females were less than 50 mm SL at the same age, size dimorphism already being apparent. Immature males exhibited higher growth rates than females during their first and second years, some of the former outstripping mature males of the preceding year class in total length. After attaining sexual maturity, both males and females grew mainly from July to December, with no significant differences in mean growth rate between them. Sexual size dimorphism of the species seems to be attributable to different growth rates between the sexes during their immature stage.     

Aneuploidy and ageing: chromosome studies on a random sample of the population using G-banding.

Chromosome analysis using G-banding was carried out on cells from 65 males and 102 females of all ages from a random sample of the population. The frequency of aneuploid cells showed a significant increase with age in both sexes, and in females the increase in hypodiploidy and hyperdiploidy was more marked than in males, and involved a high proportion of cells that had lost or gained an X chromosome, 45,X cells being much more common than 47,XXX cells. In females, the occurrence of a "fragment" of an X chromosome also correlated with increasing age, and this "fragment" appears to be an X chromosome that has simply divided prematurely at the centromere. The effects of time in culture and of repeating cultures of blood samples from the same individual on proportions of abnormal cells of various types were also investigated, and the results are discussed in the light of findings from several other "ageing surveys".     

The correlation between the frequency of sister chromatid exchanges and the kinetics of human lymphocyte proliferation: the dependence on the sex of the donor

Sister chromatid exchanges (SCE) and average generation time (AGT) were studied in lymphocytes from 35 donors (23 females and 12 males). A higher SCE frequency was found in lymphocytes from females than from males. Smoking increased SCE frequency in lymphocytes of males, but not of females. No differences in AGTs between males and females were found. Partial correlation coefficients between SCE frequency, AGT values, donor's age and smoking were determined. A statistically significant correlation (r = 0.650, P less than 0.01) between SCE frequency and AGT was found in lymphocytes obtained from females. In lymphocytes from males statistically significant partial correlation coefficients were detected between SCE frequency and AGT (r = -0.696, P less than 0.05), SCE frequency and donor's age (r = 0.770, P less than 0.01), SCE frequency and smoking intensity (r = 0.697, P less than 0.01), AGT value and donor's age (r = 0.882, P less than 0.01), and AGT value and smoking (r = 0.634, P less than 0.05). Thus, considerable differences in number of indices between males and females exist. The present observations together with other studies (D'Souza et al., 1988) suggest that considerations for population monitoring using cytogenetic techniques (ICPEMC Publication No 14) may be supplemented with the recommendation to use (whenever it possible) only males as donors in population studies.     

Genome-wide association studies for iris pigmentation and heterochromia patterns in Large White pigs

Eye colour genetics have been extensively studied in humans since the rediscovery of Mendel’s laws. This trait was first interpreted using simplistic genetic models but soon it was realised that it is more complex. In this study, we analysed eye colour variability in a Large White pig population (n = 897) and report the results of GWASs based on several comparisons including pigs having four main eye colour categories (three with both pigmented eyes of different brown grades: pale, 17.9%; medium, 14.8%; and dark, 54.3%; another one with both eyes completely depigmented, 3.8%) and heterochromia patterns (heterochromia iridis – depigmented iris sectors in pigmented irises, 3.2%; heterochromia iridum – one whole eye iris of depigmented phenotype and the other eye with the iris completely pigmented, 5.9%). Pigs were genotyped with the Illumina PorcineSNP60 BeadChip and GEMMA was used for the association analyses. The results indicated that SLC45A2 (on chromosome 16, SSC16), EDNRB (SSC11) and KITLG (SSC5) affect the different grades of brown pigmentation of the eyes, the bilateral eye depigmentation defect and the heterochromia iridis defect recorded in this white pig population respectively. These genes are involved in several mechanisms affecting pigmentation. Significant associations for the eye depigmented patterns were also identified for SNPs on two SSC4 regions (including two candidate genes: NOTCH2 and PREX2) and on SSC6, SSC8 and SSC14 (including COL17A1 as candidate gene). This study provided useful information to understand eye pigmentation mechanisms, further valuing the pig as animal model to study complex phenotypes in humans.     

Observations of physical abnormalities among the wild bonobos (Pan paniscus) of Wamba,Zaire

The wild bonobos (Pan paniscus) of Wamba, Zaire have an extremely high frequency of external abnormal traits. Out of 96 animals in a sample comprising all age and sex classes from two different natural groups, 46 individuals had at least one limb defect. The frequency of abnormalities was greater in males than in females, and increased directly with age. Almost all infants and juveniles had completely normal limbs, but virtually all males and over half the females which had reached their prime were found to have one or more limb defects. These findings indicate that congenital factors contribute little to the frequency of abnormalities in this sample. Survival rate is the same in individuals with defects as in those without defects. It appears that individual social status is far more important in procuring foods than locomotor ability. Thus, the operation of such abnormalities as a selective factor in intraspecific competition is minimized in the network of their social relations.     

Reproductive cycle of Macrobrachium amazonicum females (Crustacea, Palaemonidae).

Macrobrachium amazonicum is considered a favorite Brazilian species of freshwater prawn for cultivation as a result of its quick development and because it is easy to maintain in captivity. The aim of this work is to describe the sexual cycle stages and determine maturation age of the female M. amazonicum, which was collected monthly from June, 2002 to May, 2003 in the Jaguaribe River, Itai?aba, Ceará. A monthly sample of water was also collected to determine the following parameters: temperature, dissolved oxygen, pH and salinity. A monthly sample of females was selected among the individuals caught, to determine the total weight (W(T)), carapace length (L( C)) and abdomen+telson length (L(A+T)) and to register the number of non-ovigerous females (NOF) and ovigerous females (OF). Determining ovarian maturation stages of M. amazonicum was done in a laboratory by observing macroscopic characters such as coloring, size, location and appearance of ovarians examined by transparent carapace. The first maturation age was determined from the relative frequency of the total length (L(T)) of young and adult females. The environmental parameters of the Jaguaribe River did not hold any influence in the number of individuals collected. A total of 1,337 prawns were sampled, 513 males (38.4%) and 824 females (61.6%). The proportion between males and females in the studied population was of 1:1.6. Among the collected females, 492 (50.7%) did not carry eggs in their abdomens (NOF) and 332 (40.3%) carried eggs in their abdomens (OF). There was no record of intact females. Non-ovigerous females with mature ovaries were recorded throughout all the months of collection. The female ovaries were classified as immature (IM), rudimentary (RU), intermediary (IN) and mature (M). M. amazonicum females reach their first sexual maturity between 4.5 and 5.5 cm of total length.     

Hand osteoarthritis in the Abkhazian population

The aim of the study was to evaluate the prevalence and pattern of radiographic hand osteoarthritis (OA) in an Abkhazian community-based sample and its association with age, sex, body mass index (BMI) and place of residence.The study sample was comprised of 542 males with a mean age of 43.9, sd 15.6 years and 463 females with a mean age of 44.9, sd 13.9 years. OA was evaluated for 14 joints of the left hand according to the Kellgren and Lawrence grading scheme. Statistical analyses included prevalence estimation, multiple regression analysis and χ² tests.In the entire Abkhazian sample the average prevalence of hand OA was 33.6% for males and 35.4% for females. After age 65, the prevalence of hand OA was 87.5% for males and 83.3% for females. No sex differences were found in the prevalence or number of affected hand joints. Statistically significant association was found between the number of affected joints and BMI, but not between the prevalence of hand OA and BMI. Different prevalences of radiographic hand OA were found in individuals from different villages, after adjustment for age, sex and BMI.Additional studies are needed to explore the possible reasons for such differences.     

Meiotic disjunction and embryonic lethality in trisomies derived from an X-linked translocation in the onion fly,Hylemya antiqua (Meigen)

Translocation- and tertiary trisomies (for the X-chromosomes) were obtained after testcrossing translocation heterozygous females of an X-linked “simple” translocation stock. Meiotic disjunction as judged from segregations at M II (males) and in young eggs of testcrosses (males and females) in translocation trisomics was studied. No progeny of tertiary trisomic males and females was found, but male M II could be studied. Six different orientation types appeared in translocation trisomie (2n + 1) males and these were present in equal frequencies. No adjacent II configurations were found. The small X- and Y-chromosomes and the large translocated X-chromosome of the translocation complex disjoin at random (n and n + 1 gametes) in both translocation- and tertiary trisomic males. In translocation trisomic females four different orientation types appeared. From the high frequency of two of these (together, 94.5%) it is concluded that the two normal X-chromosomes show preferential pairing and disjunction, while the translocated X-chromosome moves to either one of the two poles at random. Primary trisomic (for the X-chromosome) males (XXY) and females (XXX) were obtained from testerossed translocation trisomics. Cytological analysis of adult male progeny of testerossed XXY males showed that no random orientation for the X-, X- and Y-chromosomes occurred because half of the sons was disomic (XY) and half of them trisomic (XXY). A possible mechanism is discussed. Analysis of young eggs of testerossed XXX females indicated a segregation of 2X∶1X=1∶1. The level of “semi”-sterility as scored from testcrosses of translocation trisomies appeared to be as in translocation heterozygotes. Here again a close relation exists between “semi”-sterility and deficiencies in eggs for a large chromosomal segment. The possible use of this translocation for genetic control of insect pests is discussed.     

Congenital hemihypertrophy. Tendency to association with other abnormalities and/or tumors

Nine cases of congenital hemihypertrophy of an entire half of the body ("true" hemihypertrophy) were investigated in relation to literature data. The left side was more often affected (7:2) and the abnormality was more frequent in females (5:4). Associated abnormalities were present in all cases: a single abnormality in 3 cases (mental retardation, iris heterochromia and, respectively, left foot gigantism) and 3 to 13 abnormalities in the other 6 cases. Prominent hemiface, asymmetric macroglossia on the affected side, unequally developed breasts, unilateral gigantism of the foot, iris heterochromia, duplication of the renal pelvis, were considered important signs which easily draw attention. Out of nine cases investigated, three presented associated tumors: two tumors, one cerebral (malignant ependymoma) and the other hepatic (cavernous hemangioma) in one case, hepatoblastoma in another case, and multiple skin angiomas in the affected side of the third one. The case presenting two tumors had also the greatest number (twelve) of associated abnormalities.     

Incidence of spontaneous ocular lesions in laboratory rabbits

Laboratory rabbits are commonly used for ocular drug and device studies. The purpose of this study was to determine the incidence of spontaneous ocular lesions in laboratory rabbits with respect to sex, breed, and supplier. We retrospectively evaluated ophthalmic examination records of rabbits screened between April 2008 and April 2010. These 1840 records represented 572 black Dutch belted (DB), 1022 New Zealand white (NZW), and 246 NZW × New Zealand red F(1) crosses (WRF1). Rabbits were between 6 and 16 wk of age and had been received from 5 suppliers. Ocular structures evaluated were the cornea, lens, iris and vitreous with respect to sex, breed and supplier. A total of 177 rabbits (9.6%) and 233 eyes (6.3%) were effected. Of total rabbits, 15.3% males and 7.3% females were affected. The most common structure affected was the cornea in 5.7% of rabbits, (DB 11.7%, NZW 3.0%, and NZR 3.3%). The lens at 3.6% was second most common (DB 2.1%, NZW 4.6%, and NZR 3.3%). Both iris (0.2%) and vitreous (0.3%) were not significantly affected. Significant sex-breeder-supplier combinations were: cornea DB supplier D, supplier D females, supplier D males, DB males and NZR females; and lens: NZW females; and at least one affected ocular structure: NZW supplier D, supplier D females, DB males, NZW females, and NZR females. Breed, sex, and supplier were significant variables of ocular lesions in laboratory rabbits. Investigators should consider each of these variables when choosing rabbits for ocular studies.     

Red cell glucose-6-phosphate dehydrogenase deficiency among Andhras

Sixty-eight Andhra males and 45 Andhra females from Visakhapatnam town of Andhra Pradesh, India have been investigated for G-6-PD deficiency. The GdB- gene has a frequency of 4.41% among males. No G-6-PH deficient females were detected. The present data have been compared with the available tribal and non-tribal data from Andhra Pradesh. It is observed that the present sample, though non-tribal in nature, presents a relatively considerable frequency of the GdB- gene.     

Age, gender and caste variations in scalp hair micro-morphological variables among Brahmins and Banias of Punjab, India

A cross-sectional sample of 3136 scalp hair drawn from 392 individuals aged 10 to 60 years and belonging to the Bania (n = 201) and Brahmin (n = 191) caste groups of Punjab State of India were examined for diameters of hair shaft and medulla, scale count, medulla type, hair index, medullary index and scale-count index, employing standard procedures. The mean hair shaft diameter, medullary diameter, incidence of medullation and scale-count index was higher in males, while the mean scale count was higher in females. However, with a few exceptions, the gender differences were not statistically significant (p < 0.05). The Brahmins showed significantly (p < 0.05) higher mean values of hair shaft diameter and scale count than the Banias. The mean scale-count index was higher among the Banias. The fragmentary medulla was the most common medullary type among the Banias, while the continuous medulla was the most frequent type of medulla among the Brahmins. The frequency of medullation was significantly more among the Banias. On the average, the hair shaft diameter and diameter of medulla increased up to 30 years. Some age variations in medullation were noticed in both the caste groups. No clear age trend was noticeable in the scale count. By and large, the mean hair shaft diameter of the Banias was less than that of other populations. The mean hair shaft diameter of the Brahmin males was greater than that of the Banias, the Onges, and the Bengalees. The Brahmin females showed greater mean hair shaft diameter than that of the Banias, the Australian Aborigines, the Juangs and the Onges. Human scalp hair shows some age, gender and population variations in micro-morphological variables which have the potential of being useful for anthropological and forensic investigations.     

Quantitative and qualitative finger dermatoglyphics in the Basque Valley of Urola, Spain

Digital dermatoglyphics of an indigenous sample of 87 males and 101 females from the Urola Valley in the Spanish Basque Country are compared with those from the nine other Basque valleys previously analyzed. In both sexes of the Urola Valley, there is a very high frequency of radial loops; the mean found in this valley extends the range of variation for South European-Mediterranean populations, and it is in the superior limit of all Caucasian populations. There are bimanual and sex differences in the frequencies of whorls and loops. Contrary to what occurs normally in populations, in the Urola Valley the frequency of whorls is higher in females and the quantitative value of digital patterns is lower in males. The results of this study show the existence of heterogeneity among valleys for digital trait frequencies and for finger ridge count, and this heterogeneity is more marked in females.     

Effect of diet and 677 C-->T 5, 10-methylenetetrahydrofolate reductase genotypes on plasma homocyst(e)ine concentrations in slovak adolescent population

The objective of this study was to evaluate the effect of diet and 677 C-->T mutation of the methylenetetrahydrofolate reductase (MTHFR) gene on plasma homocyst(e)ine concentrations in an adolescent population (113 males, age: 14.2+/-2.4 years; 202 females, age: 14.9+/-2.1 years) from a region characterized by high cardiovascular mortality. Homocyst(e)ine levels did not differ between males and females (9.4+/-3.5 and 8.9+/-3.1 micromol/l, respectively). The homozygosity for the 677 C-->T MTHFR mutation was found in 4.6 % of subjects. No differences in homocyst(e)ine levels were found between MTHFR genotypes. Analysis of the diet composition which was performed on a 24-hour daily recall basis and a food frequency questionnaire showed a low daily intake of vitamin B6 (males: 1.13 mg/66% RDA; females: 0.92 mg/61% RDA). Daily folic acid intake was 0.21 g/105% RDA in males and 0.23 g/115% RDA in females. The results of our study show that the high homocyst(e)ine levels in the adolescent population were not affected by the 677 C-->T MTHFR mutation. We conclude that an insufficient dietary intake of vitamin B6 and folic acid is responsible for this finding. This is in accord with the recommendation that the dietary allowances for folate should be reset to the originally prescribed levels of 0.4 g/day which should be sufficient to control the homocysteine levels.     

Sex- and age-specific survival of the highly dimorphic Alpine ibex: evidence for a conservative life-history tactic

1. Age-specific survival of 215 males and 117 females of the highly sexually dimorphic Alpine ibex Capra ibex (L.) was assessed from a 21-year capture-mark-recapture (CMR) programme (1983-2004). The study covered two contrasted periods of population performance (high performance from 1983 to 1997 vs. low performance from 1998 onwards). 2. Based on current life-history theories for sexually dimorphic species, we expected that survival should decrease with age in both sexes, female survival should be buffered against environmental variations, male survival should decrease during the low performance period, and adult survival should be lower in males than females during the low performance period. 3. Survival of both sexes was strongly affected by age, with the four age classes (yearling, prime-aged adults of 2-8 years of age, old adults of 8-13 years of age, and senescent adults from 13 years of age onwards) generally reported for large herbivores. 4. Survival of females at all ages, and of yearling and prime-aged males, was buffered against environmental variations and was the same during periods of high and low population performance. The survival of old males decreased in years of low population performance. 5. All marked yearlings (32 females, 56 males) survived to age 2. Survival of prime-aged females (0.996 +/- 0.011) was higher than for other large herbivores, but similarly to other large herbivore species, it declined slowly and regularly with increasing age afterwards. Male survival was 5-15% higher each year than that of males of other large herbivores. Males enjoyed very high survival when prime-aged (0.981 +/- 0.009) and as old adults (high-performance period: 0.965 +/- 0.028, low-performance period: 0.847 +/- 0.032). 6. The very high survival of males, coupled with their prolonged mass gain, suggests a highly conservative reproductive tactic. Male ibex differ from similar-sized herbivores by showing a nearly indeterminate growth in horn size and body mass. By surviving to an advanced age, males may enjoy high reproductive success because of their large size.     

Estimation of age structure by skeletochronology of a population of Hynobius nebulosus in a breeding season (Amphibia,Urodela)

Using skeletochronology, we determined the age structure of adult Hynobius nebulosus from Kyoto in the breeding season of 1998. From previously marked individuals, the lines of arrested growth proved to be formed once per year, indicating the number of winters each salamander experienced. The age at first reproduction was estimated to be 2.8-2.9 yrs of age in males and 3.8-3.9 yrs in females. The oldest males and females were 9.8-9.9 and 5.8-5.9 yrs of age, respectively, and, therefore the longevity in this species was estimated to be more than 9 yrs for males and 5 yrs for females. The growth curve of male's body size estimated indicated that the growth rate much decreases after males attained sexual maturity. Because body sizes of adults greatly vary even within an age class, it is dangerous to estimate individual age from the size frequency data at least in adults. We discussed age properties in Hynobius by comparing lentic and lotic breeders.