QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

First published online November 10, 2003

This Article Summary Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Kumashiro, M. Articles by Sakai, M. Search for Related Content PubMed PubMed Citation Articles by Kumashiro, M. Articles by Sakai, M.

Auto-spermatophore extrusion in male crickets

Mikihiko Kumashiro, Yohei Tsuji and Masaki Sakai^*

Department of Biology, Faculty of Science, Okayama University, Tsushima-Naka-3-1-1, Okayama 700-8530, Japan

View larger version (17K): [in a new window]   Fig. 1. (A) Diagram of the reproductive cycle of the male cricket. The sexually refractory stage is divided into the two substages: the first refractory stage (RS1, gray portion) between spermatophore extrusion (SE) in copulation and spermatophore preparation (SP) after copulation, and the second refractory stage (RS2, dark portion) between spermatophore preparation and the recommencement of a calling song (CS). The mating stage (MS, white portion) is the interval between the recommencement of the calling song and spermatophore extrusion. (B) Movements of the abdomen and genitalia before, during and after auto-spermatophore extrusion. (i-v) The sequence of motor actions in the posterior abdomen and external genitalia around auto-spermatophore extrusion. Abdominal contraction (Bi) starts some time after spermatophore preparation (SP). The spermatophore is extruded (Bii) with its attachment plate (not shown) ejected from the dorsal pouch of the phallic complex. Inset above Bii shows normal spermatophore extrusion during copulation with a female in which the epiphallus is hooking the subgenital plate of the female. The epiphallus is not seen but the attachment plate (AP) is observed from outside. The extruded spermatophore is soon removed (Biii-v). (C) Movements (shown as vertical bars) of the abdomen and genitalia. They are repeated together until spermatophore preparation is initiated. A, ampulla; AP, attachment plate; Auto-SE, auto-spermatophore extrusion; C, circus; Ep, epiphallus; SgP, subgenital plate; Sp, spermatophore; SPaSE, interval between spermatophore preparation and auto-spermatophore extrusion; VL, ventral lobe.

View larger version (29K): [in a new window]   Fig. 2. SPaSE in males subjected to the four different conditions. (A-D) Percentage of males exhibiting auto-spermatophore extrusion (aSE; above) or the calling song (CS; below). (A) Free-moving condition. Note the very low percentage at 50-70 min of males exhibiting auto-spermatophore extrusion (aSE) compared to males exhibiting the calling song to a female (CS). (B) Restrained condition. (C) Semi-dissected condition. (D) Dissected condition. The columns at >120 min indicate the percentage of males that did not show auto-spermatophore extrusion within 120 min. Op. (C,D) indicates the period of the 10 min operation immediately after spermatophore preparation. M, median. These conventions are also used in Figs 3 and 10.

View larger version (19K): [in a new window]   Fig. 3. SPaSE in males with the terminal abdominal ganglion (TAG) separated. (A) Connective-cut males exhibiting auto-spermatophore extrusion (A6-TAG). (B) The effect of genital stimulation (GS) with feces discharged during the operation on SPaSE in connective-cut males (A6-TAG and GS, upper). Cut, time of connective-cut. Other abbreviations and conventions as in Fig. 2.

View larger version (63K): [in a new window]   Fig. 4. Spike bursting of mDP in normal spermatophore extrusion. (A) The discharge pattern of mDP (top trace) around spermatophore extrusion induced by genital stimulation, which was started at the inverted triangle and stopped at the first bursting of mDP. mDP did not respond to the first 4.3 s, but then exhibited a strong burst (arrow), and gradually changed its discharge into a rhythmic burst after the spermatophore transfer phase (horizontal thick line). The lower trace shows the movement of the phallic complex. Each upward deflection after the spermatophore transfer phase (dots) indicates the movement of the phallic complex. (B) Discharge pattern of mDP after spermatophore extrusion. The rhythmic bursting did not stop unless the female stimulus was given. Numbers on the right indicate time (min) after spermatophore extrusion.

View larger version (30K): [in a new window]   Fig. 5. Reproducibility of discharge pattern in mDP. (A-C) Long-term recordings of mDP activity (vertical double wave symbols indicate breaks). Numbers on the right indicate time (min) after spermatophore preparation. Asterisks indicate non-bursting spontaneous spikes of mDP. White horizontal bars indicate periods between subgenital plate opening (left) and spermatophore preparation (right). x, small spikes of an unidentified neurone.

View larger version (77K): [in a new window]   Fig. 6. Spike frequency histograms of mDP (A) and x neurone (B). Spermatophore preparation (SP) occurred at time zero. SE, spermatophore extrusion elicited by artificial stimulation. These graphs were constructed from the recording in Fig. 5.

View larger version (53K): [in a new window]   Fig. 7. An x neurone identified as a DUM neurone. (A) Spike frequency histograms of two x neurones recorded from the right and left dorsal pouch nerves. r/l, spike simultaneously recorded from both the nerves; l, spike recorded from the left nerve only. (B) Recordings from the right (R) and left (L) nerves, as shown in A, at high gain. Inverted arrows indicate a synchronized spike of r/l neurone. (C) Different portion of the same recording as in B at low gain. Large spikes are from mDP. Note the absence of crosstalk.

View larger version (95K): [in a new window]   Fig. 8. DUM neurones retrogradely stained in the terminal abdominal ganglion (TAG). 7s-10s indicate the four segments of the TAG after Edwards and Palka (1974). Dendrites to the right are those of genital motor neurones, including mDP. Scale bar, 100 µm.

View larger version (38K): [in a new window]   Fig. 9. Activity of mDP in males with connectives intact. Rhythmic burst discharge is seen in the first and last lines, and sporadic spiking (asterisks) elsewhere. The break in line 3 is the time of cassette tape exchange. Arrowhead on bottom line, onset of auto-spermatophore extrusion. White bar and `x', as in Fig. 5.

View larger version (24K): [in a new window]   Fig. 10. (A,B, above) Occurrence of mDP bursting associated with auto-spermatophore extrusion. (A) Males with connectives (inset) intact. 40% of males (slashed bar) did not show burst discharge within 2 h. (B) Males with the connectives (inset) cut. `Op.' indicates a 15 min operation performed before the start of recording, and `Cut', the time of connective cut. (A,B, below) Males that recommenced their calling song (CS) after spermatophore preparation in the free-moving condition. M, median numbers.

View larger version (30K): [in a new window]   Fig. 11. Activity of mDP in males with the terminal abdominal ganglion separated. The open arrow indicates the time of connective-cut. Inset between lines 5 and 6 shows an enlarged recording of the indicated portion in which spikes with at least three different amplitudes are discerned. Scale bar for inset, 10 s. Conventions are the same as in Fig. 9.