Structure and function of the undulating membrane in spermatozoan propulsion in the toad Bufo marinus
نویسندگان
چکیده
Accessory fibers in most sperm surround the axoneme so that their function in propulsion is difficult to assess. In the sperm of the toad Bufo marinus, an accessory fiber is displaced from the axoneme, being connected to it by the thin undulating membrane in such a way that the movement of axoneme and accessory fiber can be viewed independently. The axoneme is highly convoluted in whole mounts, and the axial fiber is straight. Cinemicrographic analysis shows that it is the longer, flexuous fiber, the presumed axoneme, that move actively. The accessory fiber follows it passively with a lower amplitude of movement. The accessory fiber does not move independent of the axoneme, even after demembranation and reactivation of the sperm. On the basis of anatomical relations in the neck region, it appears that the accessory fibers of amphibians are analogous to the dense fibers of mammalian sperm. SDS polyacrylamide gel electrophoresis of demembranated toad sperm tails reveals two principal proteins in addition to the tubulins, the former probably arising from the accessory fibers and the matrix of the undulating membrane. The function of displacing an accessory fiber into an undulating membrane may be to provide stiffness for the tail without incurring an energy deficit large enough to require a long middle piece. A long middle piece is not present in toad sperm, in contrast to those sperm that have accessory fibers around the axoneme. However, the toad sperm suffers a reduction in speed of about one-third, compared with the speed expected for a sperm without an undulating membrane.
منابع مشابه
Expression of membrane transporters in cane toad Bufo marinus oocytes.
Membrane transport proteins (transporters and ion channels) have been extensively expressed in amphibian oocytes. The aims of this study were to determine whether oocytes from the cane toad Bufo marinus could be used as an alternative expression system to the broadly used Xenopus laevis oocytes. mRNAs encoding plasma membrane transporters NaSi-1 and sat-1 (sulphate transporters), NaDC-1 (dicarb...
متن کاملFood of the Marine Toad, Bufo mavinus, and Six Species of Skink in a Cacao Plantation in New Britain, Papua New Guinea
Food items from the stomachs of the toad Bufo marinus comprised 88 % snails and ants. The main single item of food of the skinks Carlia fusca, Emoia baudinii, E. callisticta, E. mivarti, Lamprolepis smaragdinum and Sphenomorphus jobiensis was lepidopteran larvae.
متن کاملLateralisation of predator avoidance responses in three species of toads.
Lateralisation of responses to presentation of a simulated predator was investigated in three species of toads: two European species (the common toad, Bufo bufo, and the green toad, Bufo viridis) and one species introduced to Australia from South America, the cane toad Bufo marinus . First a simulated snake was presented moving rapidly towards the toad in the frontal field of vision and the toa...
متن کاملThermal Dependence of Maximal Ca2+-Activated Force in Skinned Muscle Fibres of the Toad Bufo Marinus Acclimated at Different Temperatures
متن کامل
Acanthocephalus bufonis (Acanthocephala) from Bufo marinus (Bufonidae: Amphibia) in Hawaii.
During a survey of the helminth parasites of the introduced toad, Bufo marinus, on O'ahu, Hawaii, an acanthocephalan corresponding to Acanthocephalus bufonis (Shipley, 1903) was found in the intestinal tract. This is a new host and locality record for A. bufonis which has only previously been recorded from amphibians in the Orient. Possible mechanisms for the introduction of A. bufonis to Hawai...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- The Journal of Cell Biology
دوره 85 شماره
صفحات -
تاریخ انتشار 1980