The frontline : assessment of the skin bacterial communities of three species of rorquals from different environments with human impacts
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Fecha
2019
Autores
Profesor/a Guía
Facultad/escuela
Idioma
en
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Universidad Andrés Bello
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Licencia CC
Licencia CC
Resumen
Efectos de actividades humanas para la salud de los animales, son difícil de cuantificar
en la naturaleza, es por esto que el uso de especies centinelas son útiles para entender
estos fenómenos, dado ciertas características biológicas de su historia de vida, las
hacen sensibles a perturbaciones. Los cetáceos pueden ser un excelente modelo para
estudiar el efecto de actividades humanas en ecosistemas puntuales, siendo
carnívoros filtradores, su similitud con la fisiología humana e historia de vida. En la
última década y gracias al avance de técnicas de secuenciación, es que es sabido que
la microbiota juega un rol importante en la mantención de su estado de salud, esto se
ha podido extrapolar para especies silvestres, dando a conocer lo relevante que es la
microbiota para mantener la salud en especies silvestre. En grandes ballenas se ha
descrito la microbiota de la piel, en ballenas jorobadas se describió la presencia de
una comunidad microbiano central, en la cual individuos sanos deben tener la
presencia de dos géneros Tenacibaculum y Psycrobachter. El objetivo de la presente
tesis fue caracterizar la microbiota de la piel de tres especies de rorcuales presentes
en tres zonas de alimentación, ballena jorobada (BJ) (M. Novaengliae), ballena azul
(BA) (B. musculus) y ballena fin (BF) (B.physalus), presentes en tres sitios de Chile,
evaluar el efecto de variables intra-individuales (sexo, clase de edad, parentesco y
conducta), entre temporadas en BM (M. novaengliae) y BA (B. musculus) y por último evaluar el efecto del impacto humano en la microbiota de la piel de estas tres especies,
además se evaluó la presencia de enfermedades virales (Pox y Herpes virus) en las
ballenas y si existe relación entre la presencia de estas enfermedades y la microbiota.
Se muestrearon un total 96 individuos de ballenas en tres sitios de Chile, el Estrecho
de Magallanes (MS), Chiloé (CHO) y la Reserva Nacional Pingüino de Humboldt
(RNPH). Muestras de piel pertenecientes a BJ (n= 60), BA (n=29) y BF (n=9) fueron tomadas. De las BJ del estrecho de Magallanes, se obtuvieron un total de 31 adultos,
cuatro juveniles y seis crías, 11 machos y siete hembras, y dos madres con crías para
BJ de MS. Para BA de Chiloé se obtuvo un total de 15 adultos y tres juveniles, con
cinco hembras, seis machos y dos madres con crías. Se utilizó la secuenciación de la región V4 del gen 16S rRNA, la cual permitió caracterizar la microbiota de la piel de
las ballenas, cada taxón de microbioma se clasificó o como variante de secuencia de
amplicon (ASV´s). La diversidad de la microbiota de la piel reveló diferencias
significativas entre las tres especies de ballenas. La diversidad se estructuró principalmente por las variables especie (10%) y la variable geográfica (13%), y en conjunto explican el 15% de la variabilidad de la microbiota de la piel. Se encontró que
la microbiota de la piel de ballenas fue representada por especies de los géneros Cardiobacter, Moraxella, Tenacibaculum, Stenotrophomonas, Flavobacteria y
Pseudomonas. También encontramos que, de 1409 linajes detectados en el
microbioma, solo 10 ASV´s comprenden el microbioma central entre las tres especies
rorcuales, que representaron el 30% de la abundancia total. Solo se observó
diferencias en riqueza y abundancia de ASV´s entre la variable sexo en BJ y
diferencias entre temporadas. El análisis comparativo de diversidades, encontró
diferencias entre temporadas, sexo y edad, esto podría estar explicadas por las
conductas diferenciales que presentan tanto machos con hembras como en diferentes
edades. Además, se observaron ASV’s de bacterias con abundancias diferenciales en
32 ASV´s para crías, 12 para juveniles en BA y tres ASV´s para crías, cuatro ASV´s
para juveniles de BJ, lo cual podría indicar cierta colonización de bacterias en etapas
tempranas de la vida de las ballenas, la cual se focaliza en su estado adulto.
Se evaluaron 18 variables para impacto humano con efectos directos e indirectos en
cetáceos. Cuatro de estas variables explican el 18% de la variabilidad de la microbiota
de la piel. Además, se realizó un modelo (GLM) para comprobar si existe alguna
relación entre las variables antrópicas y la diversidad, se comprobó si la presencia y/o
diferentes abundancias de los géneros Tenacibaculum y Psycrobacter diferenciales
influía por zona y la detección de patógenos virales se asocia a sitios con más impacto
humano. Nuestros resultados demuestran que tanto RNPH como CHO son las zonas
con mayor impacto humano en especial para las variables embarcaciones. Se
detectaron dos individuos de BJ de RNPH y MS positivos a HV, ambos ejemplares
eran juveniles y presentaban lesiones en la piel. Nuestro modelo representa a RNPH
y CHO como las zonas con mayor impacto humano y menor diversidad, además se encontró una asociación entre la ausencia y/o baja abundancia del género
Tenacibaculum con la baja diversidad de bacterias en ciertas zonas. Creemos que, de
las variables de impacto humano, la variable tráfico de embarcaciones podría producir
mayores efectos biológicos en las ballenas, esto se vería reflejado en especial en el
género Tenacibaculum, dado que este género presenta funciones inmunológicas
sobre la piel de las ballenas.
La presente tesis contribuye a comprender las características de la microbiota de la
piel de ballenas que visitan Chile, determinar la gran variabilidad de factores que
influyen en la composición de esta comunidad bacteriana, demostrando que factores
como especie, lugar geográfico, edad, sexo, temporada e impacto humano pueden
influir de forma significativa. Es necesario realizar estudios complementarios para
profundizar en el entendimiento de cómo variables intra-individuales y ambientales
afectan a la microbiota ballenas y en consecuencia la salud de éstas. . La microbiota de
la piel de ballenas es una valiosa herramienta como bio-indicador de la salud de
ballenas y de los diferentes ecosistemas que habitan, lo cual nos entregará herramientas útiles para el manejo y conservación de las especies y lugares que
visitan.
The effect of human activities is very difficult to quantify in nature, it’s for this reason that the use of sentinel species is very useful for understanding these phenomena, given certain biological characteristics of their biological characteristics, which make them sensitive to disturbances and life history. Cetaceans can be an excellent model to study the effect of human activities on specific ecosystems, given their trophic level, their similarity to human physiology and biological characteristics. In the last decade and thanks to the advance of sequencing, it is known that the microbiota plays an important role in maintaining their health status, this has been extrapolated to wild species, giving know how relevant the microbiota is to maintain the health in wild species. In large whales, the microbiota of the skin of humpback whales has been described, describing a core microbiome, in which healthy individuals must have the presence of two genera Tenacibaculum and Psycrobachter. The objective of this thesis was to characterize the skin microbiota of three species of whales that visit Chile, Humpback whale (HW ) (M. Novaengliae), blue whale (BW) (B. musculus) and fin whale (FW) (B.physalus), presented in three Chilean sites, evaluate the effect of intraindividual variables (sex, age class, kinship and behavior), between seasons in humpback whales (M. novaengliae) and blue (B. musculus) and finally evaluate the effect of human impact on the Microbiota of the skin of the three species, the presence of viral diseases (Pox and Herpes virus) in the whales was also evaluated and if there is a relationship between the presence of these diseases and the microbiota. We sampled a total of 98 whale at three sites in Chile, the Strait of Magellan (MS), Chiloé (CHO) and the Humboldt Penguin National Reserve (HPNR), belonging to HW (n = 60), BW (n = 29) and FW (n = 9). From the HW and BW of the MS and CHO, obtaining a total of 31 adults, four juveniles and six calves´s, 11 males and seven females, and two mothers with young for HW of MS. For BW we obtained a total of 15 adults and three juveniles, with five females, six males and two mothers with calves. Using the sequencing of the VS region of the 16S rRNA gene, which allowed to characterize the microbiota of the whales' skin, each microbiome taxon is classified as an amplicon sequence variant (ASV´s). The richness and abundance revealed significant differences between the three species of whales. The diversity is structured mainly by the species variables (10%) and the location variable (13%), and together they explain 15% of the microbiota variability of the skin. In general, we found that whale skin microbiota was represented by species of the genera Cardiobacter, Moraxella, Tenacibaculum, Stenotrophomonas, Flavobacteria and Pseudomonas. We also found that, of 1409 lineages detected in the microbiome, only 10 ASVs comprise the central microbiome among the three rorcual species, which accounted for 30% of the total abundance. It was only observed differences between sex in HW for Pielou diversity and significanses differences between seasons for both species. The analysis of beta diversity showed that the composition of the core microbioma was influenced between seasons, sex and age, these differences could be explained by the differential behaviors that both males and females present at different ages. In addition, ASVs with differential abundances were observed, with 32 ASVs for calf´s and 12 ASV´s for juvenile’s BW and three ASVs for calves, 4 ASVs for juveniles of HW, which could indicate some colonization of bacteria in early stages of whale life, which focuses on its adult state. For the young and mothers of whales, the behavior and temporal stability the size was too low to draw conclusions. 18 variables were evaluated for human impact with direct and indirect effects on cetaceans. The variables National Major Ships, Small craft shipping boats, bentonic resource management and forestry activity explain the 18% of the variability of the microbiota of the skin. In addition, a model (GLM) was conducted to check if there is any relationship between the anthropic variables and the microbial diversity, if differences abundance Tenacibaculum and Psycrobacter genera influenced by area and the detection of viral pathogens is associated with sites with more human impact. Our results show that both PHNR and CHO are the areas with the greatest human impact, especially for the variables number of boats. Two individuals with HV-positive PHNR and MS HW were detected, both specimens were juveniles and had macroscopic skin lesions. Our model represents PHNR and CHO as the areas with the greatest human impact and the lowest Shannon microbiota diversity in individuals, and an association was found between the absence and / or low abundance of the Tenacibaculum genus with the low diversity of bacteria in certain areas. We believe that, of the variables of human impact, the variable vessel traffic could produce greater biological effects on whales, this would be reflected especially in the Tenacibaculum genus, since this genus has immunological functions on the skin of the whales. This thesis contributes to understand the microbiota characteristics of the skin whales that visit Chile, determine the great variability of factors that influence the composition of this bacterial community, demonstrating that factors such as species, geographical location, age class, sex, season and impact Human can influence significantly. Complementary studies are necessary to deepen the understanding of how intraindividual and environmental variables affect the microbiota whales and consequently their health. The microbiota of the skin of whales is a valuable tool like as bio-indicator of the health of whales and the different ecosystems they inhabit, which will provide us with useful tools for the management and conservation of the species and site they visit.
The effect of human activities is very difficult to quantify in nature, it’s for this reason that the use of sentinel species is very useful for understanding these phenomena, given certain biological characteristics of their biological characteristics, which make them sensitive to disturbances and life history. Cetaceans can be an excellent model to study the effect of human activities on specific ecosystems, given their trophic level, their similarity to human physiology and biological characteristics. In the last decade and thanks to the advance of sequencing, it is known that the microbiota plays an important role in maintaining their health status, this has been extrapolated to wild species, giving know how relevant the microbiota is to maintain the health in wild species. In large whales, the microbiota of the skin of humpback whales has been described, describing a core microbiome, in which healthy individuals must have the presence of two genera Tenacibaculum and Psycrobachter. The objective of this thesis was to characterize the skin microbiota of three species of whales that visit Chile, Humpback whale (HW ) (M. Novaengliae), blue whale (BW) (B. musculus) and fin whale (FW) (B.physalus), presented in three Chilean sites, evaluate the effect of intraindividual variables (sex, age class, kinship and behavior), between seasons in humpback whales (M. novaengliae) and blue (B. musculus) and finally evaluate the effect of human impact on the Microbiota of the skin of the three species, the presence of viral diseases (Pox and Herpes virus) in the whales was also evaluated and if there is a relationship between the presence of these diseases and the microbiota. We sampled a total of 98 whale at three sites in Chile, the Strait of Magellan (MS), Chiloé (CHO) and the Humboldt Penguin National Reserve (HPNR), belonging to HW (n = 60), BW (n = 29) and FW (n = 9). From the HW and BW of the MS and CHO, obtaining a total of 31 adults, four juveniles and six calves´s, 11 males and seven females, and two mothers with young for HW of MS. For BW we obtained a total of 15 adults and three juveniles, with five females, six males and two mothers with calves. Using the sequencing of the VS region of the 16S rRNA gene, which allowed to characterize the microbiota of the whales' skin, each microbiome taxon is classified as an amplicon sequence variant (ASV´s). The richness and abundance revealed significant differences between the three species of whales. The diversity is structured mainly by the species variables (10%) and the location variable (13%), and together they explain 15% of the microbiota variability of the skin. In general, we found that whale skin microbiota was represented by species of the genera Cardiobacter, Moraxella, Tenacibaculum, Stenotrophomonas, Flavobacteria and Pseudomonas. We also found that, of 1409 lineages detected in the microbiome, only 10 ASVs comprise the central microbiome among the three rorcual species, which accounted for 30% of the total abundance. It was only observed differences between sex in HW for Pielou diversity and significanses differences between seasons for both species. The analysis of beta diversity showed that the composition of the core microbioma was influenced between seasons, sex and age, these differences could be explained by the differential behaviors that both males and females present at different ages. In addition, ASVs with differential abundances were observed, with 32 ASVs for calf´s and 12 ASV´s for juvenile’s BW and three ASVs for calves, 4 ASVs for juveniles of HW, which could indicate some colonization of bacteria in early stages of whale life, which focuses on its adult state. For the young and mothers of whales, the behavior and temporal stability the size was too low to draw conclusions. 18 variables were evaluated for human impact with direct and indirect effects on cetaceans. The variables National Major Ships, Small craft shipping boats, bentonic resource management and forestry activity explain the 18% of the variability of the microbiota of the skin. In addition, a model (GLM) was conducted to check if there is any relationship between the anthropic variables and the microbial diversity, if differences abundance Tenacibaculum and Psycrobacter genera influenced by area and the detection of viral pathogens is associated with sites with more human impact. Our results show that both PHNR and CHO are the areas with the greatest human impact, especially for the variables number of boats. Two individuals with HV-positive PHNR and MS HW were detected, both specimens were juveniles and had macroscopic skin lesions. Our model represents PHNR and CHO as the areas with the greatest human impact and the lowest Shannon microbiota diversity in individuals, and an association was found between the absence and / or low abundance of the Tenacibaculum genus with the low diversity of bacteria in certain areas. We believe that, of the variables of human impact, the variable vessel traffic could produce greater biological effects on whales, this would be reflected especially in the Tenacibaculum genus, since this genus has immunological functions on the skin of the whales. This thesis contributes to understand the microbiota characteristics of the skin whales that visit Chile, determine the great variability of factors that influence the composition of this bacterial community, demonstrating that factors such as species, geographical location, age class, sex, season and impact Human can influence significantly. Complementary studies are necessary to deepen the understanding of how intraindividual and environmental variables affect the microbiota whales and consequently their health. The microbiota of the skin of whales is a valuable tool like as bio-indicator of the health of whales and the different ecosystems they inhabit, which will provide us with useful tools for the management and conservation of the species and site they visit.
Notas
Tesis (Doctor en Medicina de la Conservación)
Palabras clave
Naturaleza, Efecto del Hombre en, Ballenas, Enfermedades Bacterianas