Ecological-evolutionary relationships in Passiflora alata from Rio Grande do Sul, Brazil.

The geographical distribution, ecological characteristics, flowering and fruiting times, and pollinating agents of Passiflora alata are considered and related to molecular genetic data gathered simultaneously. The first report on this species in Rio Grande do Sul was made in 1934, only in cultivated gardens. Approximately 20 years later, however, the species was already classified as efferata (wild) in Porto Alegre's suburbs. The data presented here, together with the DNA investigations, indicate that P. alata is actively colonizing previously unoccupied areas of this region.     

Maternal and Zygotic Interactions between the Abnormal Oocyte Mutation and the Scute Inversion in DROSOPHILA MELANOGASTER

The authors have studied the interaction between the abnormal oocyte mutation and an inversion of the X chromosome, In( 1)sc⁴, which has a proximal breakpoint in or near the heterochromatic region (ABO) that maternally interacts with the abo product. It has been demonstrated that the presence of X chromosomes carrying this inversion, besides a marked increase in the severity of the maternal effect of the abo mutation, produces a zygotic effect resulting in the lethality of the progeny of stocks homozygous for abo and sc⁴. These results indicate that the sc⁴ inversion carries an abnormal region indispensable for the development of abo zygotes from sc⁴;abo mothers.     

Esterase D and carbonic anhydrase 2 in a natural population ofCebus apella from Brazil

The electrophoretic patterns of esterase D (ESD; E.C.3.1.1.1) and carbonic anhydrase 2 (CA 2, E.C.4.2.1.1) were studied in 147 specimens ofCebus apella. Three phenotypes were detected at the esterase D system,ESD ¹ allele showing a frequency of 44%, markedly different from those observed in Old World monkeys. CA2 also proved to be polymorphic, with three alleles being detected at the following frequencies:CA2 ¹, 98%;CA2 ² andCA2 ³, both 1%. The CA2 activity was absent in newborn animals and in fetuses.     

Natural hybridization betweenSaimiri taxa in the Peruvian Amazonia

A wild population situated in the border of the distributions ofSaimiri sciureus macrodon andS. boliviensis peruviensis, in the Peruvian Amazonia, was studied in relation to 22 protein loci. These genetic markers provided indications of secondary intergradation between these two taxa, reinforcing previous morphological and cytogenetic evidences. Continued studies in this region on the hybrids' viability and fertility may be important for decisions related to the taxonomy of this genus.     

Biochemical diversity and genetic distances in the Pitheciinae subfamily (primates,platyrrhini)

One hundred and forty-three sakis (Pithecia), 107 bearded sakis (Chiropotes), and 7 red uakaris (Cacajao) were studied in relation to 18 genetic loci expressed on blood through electrophoretic techniques. Eight of the 18 loci showed intrapopulational variation. The low level of genetic diversity found inPithecia could be a consequence of a decrease in populational size due to intense habitat destruction. The genetic distances between the species investigated were:Pithecia ×Chiropotes: 0.49;Pithecia ×Cacajao: 0.57;Cacajao ×Chiropotes: 0.18–0.20. These results suggest, in accordance with other data, thatChiropotes andCacajao constitute a sister group within the pithecines.     

C-bands in chromosomes 1,9, and 16 of twins

Summary Thirty-two pairs of Caucasoid twins, 16 monozygotic (MZ) and 16 dizygotic (DZ) of the same sex, were studied in relation to the C-bands of chromosomes 1, 9, and 16. Concordance was not absolute among MZ, the best evaluation of the degree of genetic determination for these traits being 0.40 for chromosome 16, 0.64 for chromosome 1, and 0.73 for chromosome 9. Possible explanations for the failure to obtain 100% concordance are methodologic shortcomings, intercell variations in chromosome contraction, and unequal mitotic crossing over.     

Eruption of permanent teeth in Brazilian Whites and Blacks

A total of 302 White and 904 Black children six, nine and 12 years of age were studied for the eruption of their permanent teeth. Differences between the two ethnic groups were not large, but the Black subjects were generally more precocious at the beginning of the process (especially the girls, both in the upper and lower incisors). At nine and 12 years of age, however, these dissimilarities disappear. The latter do not seem to be related to distinct rates of extraction or agenesis of deciduous teeth. No significant differences were observed in the degree of asymmetry present in the permanent dentition of the White and Black individuals studied.     

Senescence and human chromosome changes.

Chromosome counts and a search for structural abnormalities were performed in cultured leukocytes from 60 elderly subjects (ages 62-96) and 60 controls (ages 10-13). A total of 3900 cells were examined, 3600 in 3-day cultured and 300 in cultivations maintained for 2 days. Our results and those obtained by other investigators indicate clearly that there is an increase in the level of aneuploidy and of structural abnormalities in the blood of aged persons. There is an excess of missing C-group chromosomes in elderly females, but no consistent preferential loss was observed among the males. In contrast with two previous studies, we found a significant decrease of aneuploid cells in 3-day cultures, as compared to those cultivated for 2 days only.     

New studies on the esterase D polymorphism in South American Indians

A total of 2, 490 South American Indians affiliated with 10 tribes were studied for esterases A₁, A₂, A₃, B, D, and carbonic anhydrases 1 and 2. Wide variation was observed in the prevalence of ESD¹, the extreme values being 0. 44, encountered among the Xikrin, and 0. 95, found among the Cashinawa. Seven of the 10 frequencies fell within the interval of 0. 66–0. 87. These results were integrated with those of earlier surveys. In a general way we observe lower values in the eastern and Atlantic Coast groups, but this is mainly due to the low frequencies found among the Gê tribes and the Caingang, who speak a language which has many affinities with Gê. High prevalences were observed among the tropical forest tribes. A fair amount of intervillage, intratribal variation was found among the Ticuna and Caingang. No variability was detected in the A₁, A₂, A₃, B esterases. In the carbonic anhydrases we confirmed the presence of a “private polymorphism” among the Baniwa.     

Electrophoretic variants in three Amerindian tribes: the Baniwa, Kanamari, and Central Pano of western Brazil.

Data are presented on electrophoretic variants of 25 polypeptides found in the blood serum and erythrocytes, in 812 individuals from three Amerindian tribes, the Pano, the Baniwa, and the Kanamari. Two "private polymorphisms" were encountered, of PEPB in the Pano and CAII in the Baniwa. A single example of a different PEPB variant was encountered in the Baniwa, and two possible examples of an unstable variant of HGB A2 in the Kanamari. In addition, the well-known A variant of ACP1, the Duarte variant of GALT, the 2 variant of Hp and the 2 variant of PGM1 occurred in polymorphic proportions in all three tribes, and the TFDChi variant was present as a polymorphism in the Baniwa. These data have recently been incorporated into a treatment which concludes that the eight electrophoretically-defined "private polymorphisms" thus far encountered in Amerindian tribes can be explained by a mutation pressure of 0.7 x 10(-5)/locus/generation on the assumption of neutrality of the phenotypes in question (Neel and Thompson, '78).