Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    In: Journal of Experimental Biology, The Company of Biologists
    Abstract: The incidence of reproductive diapause is a critical aspect of life history in overwintering insects from temperate regions. Much has been learned about the timing, physiology and genetics of diapause in a range of insects, but how the multiple changes involved in this and other photoperiodically regulated traits are interrelated is not well understood. We performed quasinatural selection on reproduction under short photoperiods in a northern fly species, Drosophila montana, to trace the effects of photoperiodic selection on traits regulated by the photoperiodic timer and / or by a circadian clock system. Selection changed several traits associated with reproductive diapause, including the critical day length for diapause (CDL), the frequency of diapausing females under photoperiods that deviate from daily 24 h cycles and cold tolerance, towards the phenotypes typical of lower latitudes. However, selection had no effect on the period of free-running locomotor activity rhythm regulated by the circadian clock in fly brain. At a genomic level, selection induced extensive divergence between the selection and control line replicates in 16 gene clusters involved in signal transduction, membrane properties, immunologlobulins and development. These changes resembled ones detected between latitudinally divergent D. montana populations in the wild and involved SNP divergence associated with several genes linked with diapause induction. Overall, our study shows that photoperiodic selection for reproduction under short photoperiods affects diapause-associated traits without disrupting the central clock network generating circadian rhythms in fly locomor activity.
    Type of Medium: Online Resource
    ISSN: 1477-9145 , 0022-0949
    Language: English
    Publisher: The Company of Biologists
    Publication Date: 2019
    detail.hit.zdb_id: 1482461-9
    SSG: 12
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Online Resource
    Online Resource
    The Company of Biologists ; 1996
    In:  Journal of Experimental Biology Vol. 199, No. 11 ( 1996-11-01), p. 2383-2393
    In: Journal of Experimental Biology, The Company of Biologists, Vol. 199, No. 11 ( 1996-11-01), p. 2383-2393
    Abstract: Gymnotiform electric fish are capable of locating and approaching an electrically discharging conspecific over a range of 1–2 m in a behavior called passive electrolocation. This paper investigates the movements of two species in experiments with approaches to stationary dipoles that are either silenced or jumped to a new direction during an approach. Gymnotus carapo fail to find an electrode source in trials in which the dipole electrode is switched off in mid-track. They slow their approach, become disoriented and drift away from the target within seconds of the field being switched off. This result suggests that the fish are unable to construct a cognitive map of a dipole source from brief exposure to local electrosensory stimuli. The second set of trials shows that Brachyhypopomus diazi and Gymnotus carapo bend their body to track electric vectors which are suddenly jumped to a new direction. The latency of the bend response is 0.5 s after the jump. Bending initiates a turn that reduces to zero the error between the fish’s direction and the electric field vector and helps keep the fish aligned with the local electric field vector. Together, these experiments suggest that passive electrolocation is stimulus-bound and that these fish find the electrical sources simply by tracking instantaneous local electric current vectors.
    Type of Medium: Online Resource
    ISSN: 0022-0949 , 1477-9145
    Language: English
    Publisher: The Company of Biologists
    Publication Date: 1996
    detail.hit.zdb_id: 1482461-9
    SSG: 12
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    In: Journal of Cell Science, The Company of Biologists, Vol. 116, No. 18 ( 2003-09-15), p. 3825-3834
    Abstract: During the assembly of Plasmodium falciparum merozoites within the schizont stage, the parasite synthesizes and positions three sets of secretory vesicles (rhoptries, micronemes and dense granules) that are active during red cell invasion. There are up to 40 micronemes per merozoite, shaped like long-necked bottles, about 160 nm long and 65 nm at their widest diameter. On their external surfaces, they bear bristle-like filaments, each 3-4 nm thick and 25 nm long. Micronemes are translocated from a single Golgi-like cisterna near the nucleus along a band of two or three subpellicular microtubules to the merozoite apex, where they dock with the rhoptry tips. Dense granules are also formed around the periphery of the Golgi cisternae but their distribution is unrelated to microtubules. Three polyclonal antibodies raised against the recombinant PfAMA-1 ectodomain sequence recognizing both the 83 kDa and processed 66 kDa molecules label the peripheries of translocating and mature micronemes but do not label rhoptries significantly at any stage of merozoite development within schizonts. This result confirms that PfAMA-1 is a micronemal protein, and indicates that within the microneme it is located near or inserted into this organelle's boundary membrane.
    Type of Medium: Online Resource
    ISSN: 1477-9137 , 0021-9533
    Language: English
    Publisher: The Company of Biologists
    Publication Date: 2003
    detail.hit.zdb_id: 219171-4
    detail.hit.zdb_id: 1483099-1
    SSG: 12
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. Further information can be found on the KOBV privacy pages