The Effect of Climate Fluctuation on Chimpanzee Birth Sex Ratio

Climate and weather conditions, such as the North Atlantic Oscillation, precipitation and temperature influence the birth sex ratio (BSR) of various higher latitude species, including deer, elephant seals or northern human populations. Although, tropical regions show only little variation in temperature, climate and weather conditions can fluctuate with consequences for phenology and food resource availability. Here, we evaluate, whether the BSR of chimpanzees, inhabiting African tropical forests, is affected by climate fluctuations as well. Additionally, we evaluate, if variation in consumption of a key food resource with high nutritional value, Coula edulis nuts, is linked to both climate fluctuations and variation in BSR. We use long-term data from two study groups located in Taï National Park, Côte d'Ivoire to assess the influence of local weather conditions and the global climate driver El Niño Southern Oscillation (ENSO) on offspring sex. Côte d'Ivoire has experienced considerable climate variation over the last decades, with increasing temperature and declining precipitation. For both groups we find very similar time windows around the month of conception, in which offspring sex is well predicted by ENSO, with more males following low ENSO values, corresponding to periods of high rainfall. Furthermore, we find that the time spent cracking and feeding on Coula nuts is strongly influenced by climate conditions. Although, some of our analysis suggest that a higher proportion of males is born after periods with higher nut consumption frequency, we cannot conclude decisively at this point that nut consumption may influence shifts in BSR. All results combined suggest that also chimpanzees may experience climate related shifts in offspring sex ratios as response to climate fluctuation

Genetic diversity of HLA system in six populations from Jalisco, Mexico: Guadalajara city, Tlajomulco, Tlaquepaque, Tonalá, Zapopan and rural Jalisco

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 2046 Mexicans from the state of Jalisco living in the city of Guadalajara (N = 1189), Tlajomulco (N = 30), Tlaquepaque (N = 39), Tonalá (N = 35), Zapopan (N = 168) and rural communities (N = 585), to obtain information regarding allelic and haplotypic frequencies. We find that the most frequent haplotypes found in the state of Jalisco include nine Native American most probable ancestry and three European haplotypes. Admixture estimates revealed that the main genetic components in the state of Jalisco are European (48.45 ± 1.18 by ML; 41.66 of European haplotypes) and Native American (44.02 ± 1.24 by ML; 39.86 of Native American haplotypes), while African genetic component is less apparent (7.53 ± 0.30 by ML; 9.62 of African haplotypes)

Genetic diversity of HLA system in two populations from Colima, Mexico: Colima city and rural Colima

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 104 Mexicans from the state of Colima living in the city of Colima (N = 61) and rural communities (N = 43), to obtain information regarding allelic and haplotypic frequencies. We find that the most frequent haplotypes in the state of Colima include eight Native American, two European and one African haplotype. Admixture estimates revealed that the main genetic components in the state are Native American (52.74 ± 3.88 by ML; 48.10 of Native American haplotypes) and European (37.52 ± 8.94 by ML; 26.66 of European haplotypes), and a relatively high African genetic component (9.74 ± 8.40 by ML; 11.91 of African haplotypes). © 2019 American Society for Histocompatibility and Immunogenetic

Genetic diversity of HLA system in two populations from Nayarit, Mexico: Tepic and rural Nayarit

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 161 Mexicans from the state of Nayarit living in Tepic (N = 97) and rural communities (N = 64), to obtain information regarding allelic and haplotypic frequencies. We find that the ten most frequent haplotypes found in the state of Nayarit include eight Native American and two European haplotypes. Admixture estimates revealed that the main genetic components in the state of Nayarit are Native American (50.79 ± 5.03 by ML; 42.24 of Native American haplotypes) and European (37.04 ± 6.21 by ML; 35.72 of European haplotypes), while African genetic component is less apparent but relatively high (12.17 ± 2.50 by ML; 13.36 of African haplotypes)

Genetic diversity of HLA system in two populations from Michoacán, Mexico: Morelia and rural Michoacán

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 498 Mexicans from the state of Michoacán living in the city of Morelia (N = 150) and rural communities (N = 348), to obtain information regarding allelic and haplotypic frequencies. We find that the ten most frequent haplotypes found in the state of Michoacán include 12 Native American and two European haplotypes. Admixture estimates revealed that the main genetic components in the state of Michoacán are Native American (48.79 ± 1.44) and European (43.10 ± 0.86), while African genetic component is less apparent (8.11 ± 0.85). Our findings add to the growing knowledge on the population genetics of Western Mexico and provide new HLA data on populations from Michoacán

Genetic diversity of HLA system in three populations from Guanajuato, Mexico: Guanajuato City, León and rural Guanajuato

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 262 Mexicans from the state of Guanajuato living in the cities of Guanajuato (N = 78), León (N = 22) and rural communities (N = 162), to obtain information regarding allelic and haplotypic frequencies. We find that the most frequent haplotypes found in the state of Guanajuato include 12 Native American and three European haplotypes. Admixture estimates revealed that the main genetic components in the state of Guanajuato are Native American (50.64 ± 2.11 by ML, 43.35 of Native American haplotypes) and European (44.14 ± 1.14 by ML; 39.35 of European haplotypes), while African genetic component is less apparent (5.22 ± 2.08 by ML; 8.36 of African haplotypes)

Genetic diversity of HLA system in four populations from Baja California, Mexico: Mexicali, La Paz, Tijuana and rural Baja California

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 250 Mexicans from the states of Baja California Norte and Baja California Sur living in Mexicali (N = 100), La Paz (N = 75), Tijuana (N = 25) and rural communities (N = 50) to obtain information regarding allelic and haplotypic frequencies. The most frequent haplotypes for the Baja California region include nine Native American and five European haplotypes. Admixture estimates revealed that the main genetic components are European (50.45 ± 1.84 by ML; 42.03 of European haplotypes) and Native American (43.72 ± 2.36 by ML; 40.24 of Native American haplotypes), while the African genetic component was less apparent (5.83 ± 0.98 by ML; 9.36 of African haplotypes)

Genetic diversity of HLA system in a population sample from Aguascalientes, Mexico

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 95 Mexicans from the state of Aguascalientes to obtain information regarding allelic and haplotypic frequencies and their linkage disequilibrium. We find that the most frequent haplotypes in the state of Aguascalientes include four Native American, three European and one Asian haplotypes. Admixture estimates revealed that the main genetic components in the state of Aguascalientes are Native American (54.53 ± 3.22 by ML; 44.21 of Native American haplotypes) and European (44.34 ± 0.45 by ML; 40.53 of European haplotypes), and a relatively low African genetic component (1.13 ± 2.33 by ML; 5.26 of African haplotypes)

The immunogenetic diversity of the HLA system in Mexico correlates with underlying population genetic structure

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) allele groups and alleles by PCR-SSP based typing in a total of 15,318 mixed ancestry Mexicans from all the states of the country divided into 78 sample sets, providing information regarding allelic and haplotypic frequencies and their linkage disequilibrium, as well as admixture estimates and genetic substructure. We identified the presence of 4268 unique HLA extended haplotypes across Mexico and find that the ten most frequent (HF > 1%) HLA haplotypes with significant linkage disequilibrium (Δ’≥0.1) in Mexico (accounting for 20% of the haplotypic diversity of the country) are of primarily Native American ancestry (A*02~B*39~DRB1*04~DQB1*03:02, A*02~B*35~DRB1*08~DQB1*04, A*68~B*39~DRB1*04~DQB1*03:02, A*02~B*35~DRB1*04~DQB1*03:02, A*24~B*39~DRB1*14~DQB1*03:01, A*24~B*35~DRB1*04~DQB1*03:02, A*24~B*39~DRB1*04~DQB1*03:02, A*02~B*40:02~DRB1*04~DQB1*03:02, A*68~B*35~DRB1*04~DQB1*03:02, A*02~B*15:01~DRB1*04~DQB1*03:02). Admixture estimates obtained by a maximum likelihood method using HLA-A/-B/-DRB1 as genetic estimators revealed that the main genetic components in Mexico as a whole are Native American (ranging from 37.8% in the northern part of the country to 81.5% in the southeastern region) and European (ranging from 11.5% in the southeast to 62.6% in northern Mexico). African admixture ranged from 0.0 to 12.7% not following any specific pattern. We were able to detect three major immunogenetic clusters correlating with genetic diversity and differential admixture within Mexico: North, Central and Southeast, which is in accordance with previous reports using genome-wide data. Our findings provide insights into the population immunogenetic substructure of the whole country and add to the knowledge of mixed ancestry Latin American population genetics, important for disease association studies, detection of demographic signatures on population variation and improved allocation of public health resources.1 Introduction 2 Subjects, materials and methods 2.1 Subjects 2.2 HLA typing 2.3 Statistical analysis 2.3.1 HLA allelic and haplotypic diversity 2.3.2 Admixture proportions calculations 2.3.3 Genetic diversity and genetic substructure assessment 3 Results 3.1 HLA allele groups 3.2 Haplotypic diversity 3.3 Admixture estimates 3.4 Genetic diversity and genetic substructure assessment 4 Discussion 4.1 Admixture estimates in Mexican populations and immunogenetic diversity 4.2 The Native American immunogenetic component in Mexican populations 4.3 Implications of the study of alleles and haplotypes of the HLA system in Mexican populations and final considerations 5 Conclusio