MOLECULAR AND MORPHOLOGICAL COMPARISON BETWEEN Magnolia mexicana “YOLOXOCHITL” SPECIMENS (MAGNOLIACEAE) FROM THE STATE OF MEXICO AND VERACRUZ.

El término “Yoloxóchitl” se ha asociado históricamente con Magnolia mexicana (Magnoliaceae), especie amenazada por la disminución en sus poblaciones y áreas donde prospera. La presencia de dos árboles únicos posiblemente de esta especie en Malinalco y Zumpahuacán, Estado de México, genera interrogantes sobre su historia y alcances de su distribución. El objetivo del presente estudio fue establecer las relaciones moleculares y morfológicas existentes entre dichos individuos, con otros de M. mexicana presentes en Zongolica, Veracruz. Se colectaron muestras de tejido vegetal, y se determinaron 18 caracteres morfológicos de árboles provenientes de los municipios del Estado de México, así como de M. mexicana, provenientes de Acontla y La Quinta en Zongolica, Veracruz. Así mismo, como referentes de contraste molecular, se utilizaron muestras de M. dealbata y M. grandiflora. Se analizaron 14 iniciadores RAPD que amplificaron 205 bandas, obteniendo valores promedio PIC de 0.30 y RP de 5.42, respectivamente. Los iniciadores OPA7, OPA8 y E18 mostraron la mayor capacidad discriminante. El análisis de agrupamiento formó tres conjuntos, dos de ellos para los referentes M. grandiflora y M. dealbata, y el tercero, agrupó a M. mexicana con los individuos de Malinalco y Zumpahuacán, compartiendo una similitud genética del 87 y 90% respectivamente. Se observó además variación morfológica en 14 de 18 caracteres entre los individuos provenientes de Veracruz y los del Estado de México. Los resultados indicaron que los árboles de Yoloxóchitl de Malinalco y Zumpahuacán pertenecen a la sección Talauma, sin embargo, muestran amplia variación morfológica respecto a M. mexicana

Comparación molecular y morfológica entre ejemplares de Magnolia mexicana “Yoloxóchitl” (Magnoliaceae) del Estado De México y Veracruz

Abstract: The term "Yoloxochitl" has historically been associated with Magnolia Mexicana (Magnoliaceae), a threatened species due to the decrease in its populations and areas where it thrives. The presence of two trees possibly of this species in Malinalco and Zumpahuacan, State of Mexico, raises questions about its history and scope of its distribution. The objective of the present study was to establish the existing molecular and morphological relationships between these individuals, with others of M. mexicana present in Zongolica, Veracruz. Samples of plant tissue were collected, and 18 morphological characters of trees from the municipalities of the State of Mexico, as well as M. mexicana, from Acontla and La Quinta in Zongolica Vercruz were determined. Also, as references of molecular contrast, samples of M. dealbata and M. grandiflora were used. 14 RAPD primers were analyzed, that amplified 205 bands, obtaining average PIC values ​​of 0.30 and RP of 5.42, respectively. The cluster analysis formed three sets, two of them for the referents M. grandiflora and M. dealbata, and the third, grouped M. mexicana with the individuals of Malinalco and Zumpahuacan, sharing a genetic similarity of 87 and 90 % respectively. Morphological variation was also observed in 14 of 18 characters between individuals from Veracruz and those of the State of Mexico. The results indicated that the Yoloxochitl trees of Malinalco and Zumpahuacan belong to the Talauma section, however, they show a wide morphological variation with respect to M. mexicana.Resumen: El término “Yoloxóchitl” se ha asociado históricamente con Magnolia mexicana (Magnoliaceae), especie amenazada por la disminución en sus poblaciones y áreas donde prospera. La presencia de dos árboles únicos posiblemente de esta especie en Malinalco y Zumpahuacán, Estado de México, genera interrogantes sobre su historia y alcances de su distribución. El objetivo del presente estudio fue establecer las relaciones moleculares y morfológicas existentes entre dichos individuos, con otros de M. mexicana presentes en Zongolica, Veracruz. Se colectaron muestras de tejido vegetal, y se determinaron 18 caracteres morfológicos de árboles provenientes de los municipios del Estado de México, así como de M. mexicana, provenientes de Acontla y La Quinta en Zongolica, Veracruz. Así mismo, como referentes de contraste molecular, se utilizaron muestras de M. dealbata y M. grandiflora. Se analizaron 14 iniciadores RAPD que amplificaron 205 bandas, obteniendo valores promedio PIC de 0.30 y RP de 5.42, respectivamente. Los iniciadores OPA7, OPA8 y E18 mostraron la mayor capacidad discriminante. El análisis de agrupamiento formó tres conjuntos, dos de ellos para los referentes M. grandiflora y M. dealbata, y el tercero, agrupó a M. mexicana con los individuos de Malinalco y Zumpahuacán, compartiendo una similitud genética del 87 y 90% respectivamente. Se observó además variación morfológica en 14 de 18 caracteres entre los individuos provenientes de Veracruz y los del Estado de México. Los resultados indicaron que los árboles de Yoloxóchitl de Malinalco y Zumpahuacán pertenecen a la sección Talauma, sin embargo, muestran amplia variación morfológica respecto a M. mexicana

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

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 88 Mexicans from the state of Querétaro living in the city of Querétaro (N = 45) and rural communities (N = 43), to obtain information regarding allelic and haplotypic frequencies. We find that the most frequent haplotypes in the state of Querétaro include seven Native American, two European and one Asian haplotype. Admixture estimates revealed that the main genetic components in the state of Querétaro are Native American (51.82 ± 4.42 by ML; 42.61 of Native American haplotypes) and European (48.18 ± 3.55 by ML; 46.02 of European haplotypes), with a virtually absent African genetic component (0.00 ± 4.25 by ML; 4.55 of African haplotypes)

Genetic diversity of HLA system in a population from Guerrero, Mexico

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 144 Mexicans from the state of Guerrero to obtain information regarding allelic and haplotypic frequencies. We find that the ten most frequent haplotypes in the state of Guerrero include eight Native American and two European haplotypes. Admixture estimates revealed that the main genetic components in the state of Guerrero are Native American (61.36 ± 2.69 by ML; 54.17 of Native American haplotypes) and European (35.01 ± 4.59 by ML; 32.29 of European haplotypes), and a relatively low African genetic component (3.63 ± 2.38 by ML; 5.90 of African haplotypes)

Genetic diversity of HLA system in two populations from Chiapas, Mexico: Tuxtla Gutiérrez and rural Chiapas

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 173 Mexicans from the state of Chiapas living in the city of Tuxtla Gutiérrez (N = 52) and rural communities (N = 121), to obtain information regarding allelic and haplotypic frequencies. We found that the most frequent haplotypes in Chiapas include 12 Native American and one European haplotype. Admixture estimates revealed that the main genetic components in Chiapas are Native American (71.61 ± 0.58 by ML; 53.16 of Native American haplotypes) and European (26.39 ± 5.05 by ML; 25.86 of European haplotypes), and a less prominent African genetic component (2.00 ± 5.20 by ML; 9.77 of African haplotypes)

Genetic diversity of HLA system in six populations from Mexico City Metropolitan Area, Mexico: Mexico City North, Mexico City South, Mexico City East, Mexico City West, Mexico City Center and rural Mexico City

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 1217 Mexicans from the Mexico City Metropolitan Area living in the northern (N = 751), southern (N = 52), eastern (N = 79), western (N = 33), and central (N = 152) Mexico City, and rural communities (N = 150), to obtain information regarding allelic and haplotypic frequencies. We found that the most frequent haplotypes include 11 Native American haplotypes. Admixture estimates revealed that the main genetic components are Native American (63.85 ± 1.55 by ML; 57.19 of Native American haplotypes) and European (28.53 ± 3.13 by ML; 28.40 of European haplotypes), and a less apparent African genetic component (7.61 ± 1.96 by ML; 7.17 of African haplotypes)

Genetic diversity of HLA system in two populations from Hidalgo, Mexico: Pachuca and rural Hidalgo

We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) alleles by PCR-SSP based typing in 122 Mexicans from the state of Hidalgo living in the city of Pachuca (N = 41) and rural communities (N = 81), to obtain information regarding allelic and haplotypic frequencies. We find that the most frequent haplotypes in Hidalgo include eight Native American and one European haplotypes. Admixture estimates revealed that the main genetic components in Hidalgo are Native American (58.93 ± 2.16 by ML; 54.51 of Native American haplotypes) and European (32.49 ± 2.88 by ML; 28.69 of European haplotypes), and a relatively high African genetic component (8.58 ± 0.93 by ML; 6.97 of African haplotypes)

Dynamic behaviour of the East Antarctic ice sheet during Pliocene warmth

Warm intervals within the Pliocene epoch (5.33–2.58 million years ago) were characterized by global temperatures comparable to those predicted for the end of this century1 and atmospheric CO2 concentrations similar to today2, 3, 4. Estimates for global sea level highstands during these times5 imply possible retreat of the East Antarctic ice sheet, but ice-proximal evidence from the Antarctic margin is scarce. Here we present new data from Pliocene marine sediments recovered offshore of Adélie Land, East Antarctica, that reveal dynamic behaviour of the East Antarctic ice sheet in the vicinity of the low-lying Wilkes Subglacial Basin during times of past climatic warmth. Sedimentary sequences deposited between 5.3 and 3.3 million years ago indicate increases in Southern Ocean surface water productivity, associated with elevated circum-Antarctic temperatures. The geochemical provenance of detrital material deposited during these warm intervals suggests active erosion of continental bedrock from within the Wilkes Subglacial Basin, an area today buried beneath the East Antarctic ice sheet. We interpret this erosion to be associated with retreat of the ice sheet margin several hundreds of kilometres inland and conclude that the East Antarctic ice sheet was sensitive to climatic warmth during the Pliocene

Dynamic behaviour of the East Antarctic ice sheet during Pliocene warmth

Warm intervals within the Pliocene epoch (5.33-2.58 million years ago) were characterized by global temperatures comparable to those predicted for the end of this century and atmospheric CO 2 concentrations similar to today. Estimates for global sea level highstands during these times imply possible retreat of the East Antarctic ice sheet, but ice-proximal evidence from the Antarctic margin is scarce. Here we present new data from Pliocene marine sediments recovered offshore of Adélie Land, East Antarctica, that reveal dynamic behaviour of the East Antarctic ice sheet in the vicinity of the low-lying Wilkes Subglacial Basin during times of past climatic warmth. Sedimentary sequences deposited between 5.3 and 3.3 million years ago indicate increases in Southern Ocean surface water productivity, associated with elevated circum-Antarctic temperatures. The geochemical provenance of detrital material deposited during these warm intervals suggests active erosion of continental bedrock from within the Wilkes Subglacial Basin, an area today buried beneath the East Antarctic ice sheet. We interpret this erosion to be associated with retreat of the ice sheet margin several hundreds of kilometres inland and conclude that the East Antarctic ice sheet was sensitive to climatic warmth during the Pliocene. © 2013 Macmillan Publishers Limited. All rights reserved

Dynamic behaviour of the East Antarctic ice sheet during Pliocene warmth

Warm intervals within the Pliocene epoch (5.33-2.58 million years ago) were characterized by global temperatures comparable to those predicted for the end of this century and atmospheric CO 2 concentrations similar to today. Estimates for global sea level highstands during these times imply possible retreat of the East Antarctic ice sheet, but ice-proximal evidence from the Antarctic margin is scarce. Here we present new data from Pliocene marine sediments recovered offshore of Adélie Land, East Antarctica, that reveal dynamic behaviour of the East Antarctic ice sheet in the vicinity of the low-lying Wilkes Subglacial Basin during times of past climatic warmth. Sedimentary sequences deposited between 5.3 and 3.3 million years ago indicate increases in Southern Ocean surface water productivity, associated with elevated circum-Antarctic temperatures. The geochemical provenance of detrital material deposited during these warm intervals suggests active erosion of continental bedrock from within the Wilkes Subglacial Basin, an area today buried beneath the East Antarctic ice sheet. We interpret this erosion to be associated with retreat of the ice sheet margin several hundreds of kilometres inland and conclude that the East Antarctic ice sheet was sensitive to climatic warmth during the Pliocene. © 2013 Macmillan Publishers Limited. All rights reserved