RESUMO
Assisted gene flow (AGF) is a conservation intervention to accelerate species adaptation to climate change by importing genetic diversity into at-risk populations. Corals exemplify both the need for AGF and its technical challenges; corals have declined in abundance, suffered pervasive reproductive failures, and struggled to adapt to climate change, yet mature corals cannot be easily moved for breeding, and coral gametes lose viability within hours. Here, we report the successful demonstration of AGF in corals using cryopreserved sperm that was frozen for 2 to 10 y. We fertilized Acropora palmata eggs from the western Caribbean (Curaçao) with cryopreserved sperm from genetically distinct populations in the eastern and central Caribbean (Florida and Puerto Rico, respectively). We then confirmed interpopulation parentage in the Curaçao-Florida offspring using 19,696 single-nucleotide polymorphism markers. Thus, we provide evidence of reproductive compatibility of a Caribbean coral across a recognized barrier to gene flow. The 6-mo survival of AGF offspring was 42%, the highest ever achieved in this species, yielding the largest wildlife population ever raised from cryopreserved material. By breeding a critically endangered coral across its range without moving adults, we show that AGF using cryopreservation is a viable conservation tool to increase genetic diversity in threatened marine populations.
Assuntos
Antozoários/genética , Fluxo Gênico/genética , Espermatozoides/fisiologia , Animais , Conservação dos Recursos Naturais/métodos , Recifes de Corais , Criopreservação/métodos , Espécies em Perigo de Extinção , Fertilização/genética , Florida , Genética Populacional/métodos , Células Germinativas/fisiologia , Masculino , Porto Rico , Reprodução/genéticaRESUMO
BACKGROUND: Rates of low birthweight and prematurity vary 2-fold across states in the United States, with increased rates among states with higher concentrations of racial minorities. Medicaid expansion may serve as a mechanism to reduce geographic variation within states that expanded, by improving health and access to care for vulnerable populations. OBJECTIVE: The objective of this study was to identify the association of Medicaid expansion with changes in county-level geographic variation in rates of low birthweight and preterm births, overall and stratified by race/ethnicity. RESEARCH DESIGN: We compared changes in the coefficient of variation and the ratio of the 80th-to-20th percentiles using bootstrap samples (n=1000) of counties drawn separately for all births and for white, black, and Hispanic births, separately. MEASURES: County-level rates of low birthweight and preterm birth. RESULTS: Before Medicaid expansion, counties in expansion states were concentrated among quintiles with lower rates of adverse birth outcomes and counties in nonexpansion states were concentrated among quintiles with higher rates. In expansion states, county-level variation, measured by the coefficient of variation, declined for both outcomes among all racial/ethnic categories. In nonexpansion states, geographic variation reduced for both outcomes among Hispanic births and for low birthweight among white births, but increased for both outcomes among black births. CONCLUSIONS: The decrease in county-level variation in adverse birth outcomes among expansion states suggests improved equity in these states. Further reduction in geographic variation will depend largely on policies or interventions that reduce racial disparities in states that did and did not expand Medicaid.