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‘ In Vitro ’ Capacitation and Acrosome Reaction are Concomitant with Specific Changes in Mitochondrial Activity in Boar Sperm: Evidence for a Nucleated Mitochondrial Activation and for the Existence of a Capacitation‐Sensitive Subpopulational Structure
Author(s) -
RamióLluch L,
FernándezNovell JM,
Peña A,
Colás C,
CebriánPérez JA,
MuiñoBlanco T,
Ramírez A,
Concha II,
Rigau T,
RodríguezGil JE
Publication year - 2011
Publication title -
reproduction in domestic animals
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.546
H-Index - 66
eISSN - 1439-0531
pISSN - 0936-6768
DOI - 10.1111/j.1439-0531.2010.01725.x
Subject(s) - capacitation , sperm , andrology , acrosome reaction , staining , boar , mitochondrion , acrosome , biology , medicine , biochemistry , genetics
Contents The main scope of this manuscript is to analyse the dynamics of mitochondrial activity in boar sperm subjected to ‘ in vitro ’ capacitation (IVC) and subsequent progesterone‐induced ‘ in vitro ’ acrosome reaction (IVAR). This was determined after analysis of the rhythm of O 2 consumption and concomitant changes in the mitochondria activity‐specific JC‐1 staining. Results showed that IVC, and especially IVAR, was concomitant with a peak in O 2 consumption (from 1.61 ± 0.08 nmol O 2 /min/10 7 viable sperm at 0 h of incubation to 2.62 ± 0.12 nmol O 2 /min/10 7 viable sperm after 5 min of IVAR induction). These results were accompanied by parallel changes in the mean intensity of JC‐1 staining. Based on JC‐1, mitochondrial activation followed a nucleated pattern, with specific, activation starting points at the midpiece from which mitochondrial activation was spread. Moreover, four separate sperm subpopulations were detected following the JC‐1 orange‐red/green ratio, and the observed changes in the mean JC‐1 staining during IVC and IVAR were related to concomitant changes in both the orange‐red/green JC‐1 ratio and the percentage of sperm included in each subpopulation. All of these results indicate that IVC and the first minutes of IVAR are accompanied by a progressive increase in mitochondrial activity, which reached a peak coincidental with the achievement of IVAR. Moreover, results suggest the presence of separate sperm subpopulations, which show a different mitochondrial sensitivity to IVC and IVAR. Finally, mitochondrial activation, at least under JC‐1 staining, seems to originate in concrete nucleation points at the midpiece, thus suggesting thus a well‐coordinated pattern in boar‐sperm mitochondrial activity modulation.