Polygonia C-aureum Research Articles

Separation of Bombyxin from a neuropeptide of Bombyx mori showing Summer-morph-producing Hormone (SMPH) activity in the Asian Comma Butterfly, Polygonia c-aureum L.

A neuropeptide from brain-suboesophageal ganglion (Br–SG) complexes of the silkmoth, Bombyx mori, shows summer-morph-producing hormone (SMPH) activity in the Asian comma butterfly, P. c-aureum. The SMPH-active peptide was extracted and demonstrated to be almost the same molecular size as bombyxin (4–5 kD), a nueropeptide which shows prothoracicotropic hormone (PTTH) activity when assayed in vitro with prothoracic glands (PGs) of 4th-instar B. mori larvae in vitro. A Sephadex G-50 fraction of 3–8 kD molecules prepared from Br–SG complexes of B. mori adults was applied to CM-, SP-, DEAE- or QAE- Toyoperal columns at pH 5.6 (or pH 6.9). The SMPH-activity could be separated from the PTTH-activity (or bombyxin) by subjecting a SMPH- and PTTH-active preparation of B. mori to anion-exchange chromatography at pH 6.9. By reversed-phase HPLC following an anion-exchange chromatography, SMPH-activity was recovered in two fractions of 40–45% acetonitril. Results demonstrate that the B. mori peptide showing the SMPH-activity in P. c-aureum is a different molecule than bombyxin.

Effects of Photoperiod and Age on the Initiation of Sperm Movement in Male Polygonia c-aureum LINNAEUS (Lepidoptera: Nymphalidae)

Effects of Photoperiod and Age on the Initiation of Sperm Movement in Male Polygonia c-aureum LINNAEUS (Lepidoptera: Nymphalidae)

Regulation of Sperm Quantity Transferring to Females at Mating in the Adult Male of Polygonia c-aureum (Lepidoptera: Nymphalidae)

The dynamics of sperms in the male reproductive organs during copulation was investigated with a nymphalid butterfly, Polygonia c-aureum. It was demonstrated that the males did not transfer all the sperms stored in the duplex to females by one mating. As soon as mating occurred, sperms in the duplex began to flow back to the middle vas deferens, but it seemed to stop on the way of mating. Sperms still remained in the duplex were then ejaculated to the female. This means that part of sperms existed in the duplex before mating were used for the insemination. Since sperms moved from the vas deferens into the duplex again shortly after mating, they probably could be used at the next mating. The significance of this sperm movement specific at mating is discussed.

Effects of Photoperiod and Temperature on Several Pupal Characters Associated with Imaginal Polyphenism in Polygonia c-aureum(Lepidoptera:Nymphalidae)

Effects of Photoperiod and Temperature on Several Pupal Characters Associated with Imaginal Polyphenism in Polygonia c-aureum(Lepidoptera:Nymphalidae)

Neuroendocrine Regulation of the Development of Seasonal Forms of the Asian Comma Butterfly, Polygonia c-aureum L: (neurosecretion/seasonal form/butterfly (Polygonia c-aureum)).

In the butterfly, Polygonia c-aureum, development of seasonal forms controlled by the photoperiod and temperature was shown to involve a neuroendocrine system of the brain-corpus cardiacum-corpus allatum complex. For analysis of the neuroendocrine system concerned, the innervation of the complex was investigated first by cobalt chloride perfusion staining and then by severance of axons, ablation of the candidate cells, injection of a homogenate of these cells and transplantation of corpora cardiaca using pupae programmed to be either summer-form or autumn-form adults. The results suggested that medial nerve cells produce what is called material producing the summer form. The seasonal forms of the Asian comma butterfly, Polygonia c-aureum L., summer and autumn forms (Fig. la, b), are determined by the photoperiod and the temperature during the larval period (1-3). Previous studies have given the following results on the physiological mechanism involved in the effect of environmental factors in inducing these seasonal forms. First, the mechanism involves neurosecretory cells located somewhere in the brain (2). Second, the nervous connections between the brain and the corpus cardiacum (NCC I+II (4)) and between the right and left brain lobes are indispensable for the effect (2, 5-7). The present study consisted of two series of experiments. One was designed to demonstrate morphologically the axonal connection of the corpus cardiacum with the corpus allatum in this butterfly, like that shown in several other insects (8-13). The other series was designed to locate the neurosecretory cells producing material related to the seasonal form and to see if this material is also present in the corpus cardiacum.

ACTIVATION OF THE CORPORA ALLATA IN RELATION TO OVARIAN MATURATION IN THE SEASONAL FORMS OF THE BUTTERFLY, POLYGONIA C-AUREUM L.

In Polygonia c-aureum, there are two seasonal forms, viz., the summer form and the autumn form. Previous experiments (Endo, 1970) showed that the corpora allata of the summer form accelerate the maturation of ovarian follicles soon after imaginal ecdysis. On the other hand, the corpora allata of the autumn form do not stimulate ovarian maturation during a period of 2 to 3 weeks after the emergence. In the summer form (S) as well as in the autumn form (A), the corpora allata remained in an inactive state for about 15 days after emergence when they had been isolated microsurgically from the brain and the corpora cardiaca during the larval period. Further, when separation of the brain into the right and left hemispheres or ablation of the medial neurosecretory group cells of the pars intercerebralis had been carried out on S-pupae of 28 hr after pupation or of earlier ages, they developed into autumn form in respect to wing pattern and their corpora allata did not stimulate ovarian maturation until 2 to 3 weeks after emergence. On the other hand, when the above operations had been performed 34 hr after the pupation or of later ages, they developed into summer form in respect to wing pattern and ovarian maturation was evident soon after the emergence. In these cases, stimulation of the corpora allata is closely connected with the development of seasonal-forms of wing pattern. From these experiments, it is clear that the medial neurosecretory group cells of the pars intercerebralis in S-insects stimulate the corpora allata about 30 hr after pupation by way of the nervi corporis cardiaci and the activated corpora allata promote ovarian maturation throughout adult life. In A-insects, on the other hand, the medial neurosecretory group cells of the brain are inactive and fail to activate the corpora allata which in turn have no influence on ovarian maturation.

Some observations on the ovipositing habit and the larval food plants of Polygonia c-aureum LINNE

Some observations on the ovipositing habit and the larval food plants of Polygonia c-aureum LINNE

Relation between ovarian maturation and activity of the corpora allata in seasonal forms of the butterfly, Polygonia c-aureum L.

In summer form adults of Polygonia c-aureum, the ovary develops soon after emergence and eggs mature a few days later. However, in autumn form adults, having been kept in laboratory conditions, only several mature eggs are found about four weeks after emergence. The allatectomy during the larval period prevents egg maturation in adults of both forms. When the corpora allata from the summer form of both sexes are transplanted into allatectomized adults of the autumn or summer form, the ovary develops as in the case of summer form adults. But the corpora allata of both sexes of the autumn form are not effective in inducing the ovarian maturation. Environmental factors, especially day-length and temperature during the larval period, may act through the neuroendocrine system to induce the activity of the corpora allata in the adult life.

Hormonal Control of the Development of Seasonal Forms in the Butterfly, Polygonia c-aureum L

Hormonal Control of the Development of Seasonal Forms in the Butterfly, Polygonia c-aureum L