松褐天牛的交配行为

采用室内试验和野外观察相结合的方法,对松材线虫病的主要媒介昆虫松褐天牛Monochamus alternatus Hope的交配行为进行了研究。结果表明： 松褐天牛一次完整的交配包括相遇抱对、插入输精和配后保护3个阶段,在交配过程中雄虫有多次插入输精现象发生。室内试验中共观察到松褐天牛的交配123次,松褐天牛一次完整的交配过程平均需时63.49 min,其中输精前的抱对时间平均为1.68 min,交配过程中每次输精插入时间平均为57.60 s,配后保护时间为15.18 min。松褐天牛在开始交配的4天内平均交配5.15次,不同雄性个体所获得的交配机会差异很大。松褐天牛的交配行为表现出强烈的雄性竞争现象,雄虫能根据雌虫或自身的交配经历调整交配投入,当雌虫或者雄虫是初次交配时,总输精时间和插入输精的次数显著大于与有交配经历的雌虫或雄虫交配时的输精时间和插入输精次数。田间松褐天牛的交配行为与室内观察结果基本一致。     

甜菜夜蛾交配行为和能力

在(27±1)℃,光周期L14∶D10的条件下对甜菜夜蛾I>Spodoptera exigua的交配行为及能力进行了研究。结果表明：成虫在羽化当晚即可进行交配,交配率以羽化后头三个晚上的较高(>82%),但从第4天起则显著下降。成虫一天中的交配时间出现于23:30～05:30之间,交配高峰出现在01:30～02:30和03:00～04:00 之间, 其中以第1高峰的发生频率较高。成虫交配持续时间从22～191 min不等,但以30～60 min的为多(40.8%, n=97), 60～90 min的次之(19.4%),超过180 min的较少(10.2 %)。另外,交配持续时间与蛾龄紧密相关。蛾龄越大,交配持续的时间越长,且差异显著。雄蛾一生的交配能力由1～11次不等,但受性比的影响显著：在性比为1∶1的条件下,雄蛾平均交配次数仅为3.0 次,而在2♀∶1♂至5♀∶1♂时,则增加到5.1～6.0 次。雌蛾交配比例及次数受性比的影响也很大：没有交配的雌蛾比例从1∶1时的8.3%增加到5♀∶1♂时的32%,仅交配一次的比例从16.7%增加到38.7%,而交配≥5 次的比例则从 25%下降到0。最后,对这些结果在甜菜夜蛾防治中应用的可能性进行了讨论。     

Mating Type Inheritance in Glaucoma*

SYNOPSIS. Mating was observed in collections of Glaucoma from 2 localities in Illinois. The collections could be divided into 2 syngens on the basis of mating type reactions. Corticotype analysis showed that syngen 1 was intermediate in meridian number between Glaucoma chattoni and Glaucoma scintillans, while syngen 2 had the same range as Glaucoma scintillans (Lee, unpublished). The major features of mating type inheritance in syngen 1 are that exconjugant clones usually have identical mating types and that mating types I and II appear in an approximately 1:1 ratio in successive generations. This is the result expected in genic mating type inheritance if one of the original parents was a homozygote and the other a heterozygote at the mating type locus. No significant immaturity period was found in these strains. Only 2 viable pairs were obtained from syngen 2 crosses, but results from these suggest that mating type inheritance may be epigenetic and a longer immaturity period may characterize this syngen.     

大猿叶虫交配行为的观察

大猿叶虫Colaphellus bowringi Baly是十字花科上的重要害虫,一生能多次交配。本试验在25℃,光周期L∶D=12∶12条件下观察了大猿叶虫成虫连续7d的交配行为。结果表明:(1)每日平均交配(5.67±0.26)次,最高可达11次,不同日龄间的交配次数存在显著差异。(2)平均每日用于交配的时间为(238±10)min,占总时间的33.5%,最长可达493min,占总时间的68.5%,不同日龄间的交配时间有极显著差异。(3)交配持续时间最短8min,最长达289min,平均为(48±2)min;同一日内,随着交配次数增加,交配持续时间逐渐缩短;不同日龄间的交配持续时间存在显著差异。(4)相邻两次交配之间的间隔时间最短5min,最长300min,平均交配间隔(75±3)min;交配间隔时间随日龄的增加而明显延长。     

Mating aggregates in Escherichia coli conjugation.

Mating mixtures of Escherichia coli cells were shown to contain mating aggregates of two to 20 cells each rather than only mating pairs of two cells each. The mating aggregate size distribution shows two broad peaks, at two to four cells and at eight to 13 cells. The quantitative mating aggregate size distribution and the proportion of male cells in mating aggregates are dependent on the input ratio of male to female cells. At an input ratio of one to one, the average mating aggregate contains equal proportions of male and female cells and most of the cells involved in mating are in large aggregates of seven or more cells each. The deoxyribonucleic acid (DNA) transfer efficiency per mating aggregate cell was constant regardless of average aggregate size or of the ratio of male to female cells in the aggregate. Under optimal conditions essentially every male cell or every female cell in a mating aggregate can be involved in DNA transfer. A comparison of light microscopy, sucrose gradient centrifugation, and analysis with a modified Coulter counter indicated that the number of cells in mating aggregates is best equantitated using a modified Coulter counter.     

Mating behavior of the cabbage beetle, Colaphellus bowringi (Coleoptera: Chrysomelidae)

Abstract  Circadian mating rhythms, mating frequency, mating duration, and the effect of mating duration on fecundity and fertility in the cabbage beetle, Colaphellus bowringi were investigated in the laboratory. Mating occurred throughout the 24-h cycle but the majority of copulations occurred in the photophase with two apparent peaks, one at 8:00 and another at 16:00. Mating frequency observations for 10 consecutive days indicated that pre-mating period of C. bowringi was about 4 days, and pairs mated an average of 5 times per day and an average of 40 times during the first 10 days. There was a negative correlation between mating frequency and mating duration during the consecutive mating. The mean duration of the first copulation (136.24 ± 4.62 min) was significantly longer than those of the second (57.87 ± 2.03 min), third (53.05 ± 2.05 min) and fourth copulation (30.86 ± 2.98 min). Fecundity showed a slight increase with increasing mating duration but no significant difference among treatments. However, fertility was significantly influenced by the mating duration in this species. Mating of 20-min duration did not produce viable eggs. The mean percentage of fertile eggs with completed mating duration (204.43 ± 18.96 min, 56.75% fertile eggs) was significantly higher than those with 60 min (39.55%) and 30 min (17.91%) mating duration, suggesting that the longer mating duration might be associated with transfer of more sperm that are used to increase the fertility of eggs.     

Interaction between Different Mating Types in Heterothallic Strains of Closterium peracerosum-strigosum-littorale: Effects on Expansion of Colony

When Closterium cells were embedded in an agar disk which wasplaced on an agar plate, the cells migrated out of the agardisk and formed a circular colony on the surface of the agarplate. Expansion of the colony was affected by interaction betweendifferent mating type cells. (Received November 20, 1982; Accepted May 6, 1983)     

Mating type differentiation in Tetrahymena thermophila: Strong influence of delayed refeeding of conjugating pairs

Mating type differentiation in Tetrahymena thermophila is known to regularly involve stable hereditary alterations at a single chromosomal locus in the somatic (macro)nucleus. This differentiation is directionally affected by the temperature at which new macronuclei develop after fertilization. We now report large and predictable effects of delayed refeeding of conjugating pairs upon mating type differentiation, particularly among mat-2 homozygotes. The mating types whose frequency is affected the most are IV, VI, and VII, a set different from that most affected by temperature. We interpret our observations to reveal the existence of a second system which can participate in mating type differentiation, with different specificity from the system influenced by temperature under conditions of early refeeding of conjugating pairs. These observations enrich the phenomenology surrounding mating type differentiation in T thermophila and provide additional, easily controllable experimental conditions for the manipulation of mating type frequencies.     

Mating Types and Mating Type Inheritance in Euplotes minuta Yocom (Ciliata, Hypotrichida)

SYNOPSIS. Thirty-one stocks of a marine ciliate, Euplotes minuta Yocom, collected from different localities, can be grouped in seven mating types. True pairs are formed only in mixtures of stocks belonging to different mating types. No selfing pairs or intraclonal conjugation have ever been observed. Synclonal inheritance of mating types is the rule, although about 10% of pairs show clonal inheritance. The latter can be explained by assuming syncaryon formation through cytogamy or through caryogamy of pronuclei derived from different products of meiosis. Mating type determination is due to 7 alleles at the single locus mt . There is complete dominance among the 7 alleles which can be orderly seriated, as shown in Table 3, according to their dominance relationship. The 5 stocks, and only these 5, of mating type VII have the autogamy trait. The mortality rate in F₁ and F₂ is very low–a maximum of 10%; however, the F₂'S obtained by autogamy from F₁ progenies in which mating type VII is involved have a very high mortality rate. The two facts (high mortality rate in F₂ and strict association of autogamy trait with mating type VII in natural populations) have been considered as evidences of a probable isolation mechanism existing between mating type VII and the other 6 mating types. Thus, the 7 mating types have been assigned to the same syngen only tentatively.     

圈养条件下金钱豹交配行为的初步观察

2005年3月至2006年3月,采取所有事件取样法,对成都动物园5只(2雄,3雌)圈养金钱豹(Panthera pardu)进行观察,旨在了解圈养金钱豹的交配情况。记录交配行为1 174次。结果显示,圈养金钱豹全年皆可发情。具有明显的交配模式,交配姿势仅有一种,为背腹式。平均交配持续天数为(4.75±1.26)d。昼夜都有交配行为,但白天交配次数较夜间多。日交配的高峰发生在08:00～10:00时,不同的雄性个体出现的交配高峰日不同。平均交配持续时间为(7.48±1.22)s。在交配持续时间(P=0.000)、总交配次数(P=0.04)上,不同的雄性个体间存在显著性差异;而同一雄性在与不同雌性交配时,其持续时间无显著差异。金钱豹交配的特点为,交配的频次多,但每次交配持续时间短。     

Detection and Evaluation of an Inducer of a Diffusible Mating Pheromone of the Heterothallic Closterium peracerosum-strigosum-littorale Complex

When mating-type plus cells of the Closterium peracerosum-strigosum-littoralecomplex were incubated in nitrogen-deficient medium obtainedfrom a 24-h-old mixed culture of mating-type plus and mating-typeminus cells, protoplast-release-inducing activity specific formating-type minus cells was detected in the medium. When mating-typeplus cells were incubated in the medium from a culture of exclusivelymating-type minus cells, protoplast-release-inducing activitywas also detected. These results suggested the existence ofa substance, released from mating-type minus cells, that hasthe ability to make mating-type plus cells release protoplast-release-inducingprotein (PR-IP). We designated it PR-IP Inducer. The PR-IP Inducerwas constitutively released from mt^– cells in the light.The PR-IP Inducer was heat-labile and had a relative molecularweight of 10,000 on gel filtration. We suggest that the PR-IPInducer is also a pheromonal substance that plays a role inthe initial events in the sexual communication of this Closteriumcomplex. (Received April 26, 1993; Accepted July 15, 1993)     

(−) Mating Type-Specific Mutants ofPhycomycesDefective in Sex Pheromone Biosynthesis

Sutter, R. P., Grandin, A. B., Dye, B. D., and Moore, W. R. 1996. (−) Mating type-specific mutants ofPhycomycesdefective in sex pheromone biosynthesis.Fungal Genetics and Biology20,268–279. We have isolated the first mating type-specific mutants in mucoraceous fungi. Both mutants inPhycomyces blakesleeanusappear to be defective in the same gene. The gene, present in both mating types, is necessary only in cultures of the (−) mating type. The gene codes for an enzyme in sex pheromone biosynthesis. The pheromone precursor made by the mutants is detectable only in cross-feeding experiments. The biological and solubility properties of the precursor suggest the precursor is 4-dihydrotrisporin, a metabolite of β-carotene. Separate studies with β-carotene-deficient mutants and Compound-P, a new chemically synthesized precursor of the pheromones, imply the constitutive level of enzymes for pheromone biosynthesis inPhycomycesis extremely low. In comparison, the level of enzymes for pheromone conversion to trisporic acid is higher. The mating type-specific mutants also catalyze the conversion of (+) pheromone to trisporic acid. This finding was unexpected because literature models predicted this reaction was catalyzed by the same enzyme which catalyzed the conversion of 4-dihydrotrisporin to (−) pheromone—a reaction missing in the (−) mating type-specific mutants. Thus, we propose a revised model for trisporic acid biosynthesis.     

Mating type differentiation in tetrahymena thermophila: Characterization of the delayed refeeding effect and its implications concerning intranuclear coordination

Mating type determination in Tetrahymena thermophila involves developmentally programmed, heritable alterations of the macronucleus, localized to the mtd locus. This determination can be predictably controlled by the environmental conditions during macronuclear development, eg, temperature and time of refeeding. In this article we have further characterized the effects of delayed refeeding on mating type determination, as revealed by the frequency of mating types among the progeny of a cross. Our results show that 1) the magnitude of this starvation effect decreases with temperature of conjugation and becomes undetectable at 18°C; 2) starvation during the interval 14 to 22 hr (after conjugation is induced at 30°C) is a necessary and sufficient condition for the induction of starvation effects; 3) relative mating type frequencies vary monotonically with nutrient concentration present during this critical period; and 4) sister macronuclei, developing under starvation conditions in the same cytoplasm, differentiate majority mating types characteristic of early or late refeeding; sister macronuclei show no apparent correlation with each other. On the basis of our observations on early and late refed cells, we propose that the composition of the newly developed macronucleus is the outcome of two key events: 1) mating type determination at the mtd locus and 2) differential molecular cloning of generally one or two autonomously replicating fragments (ARFs) of the macronuclear DNA bearing the mtd locus.     

Interconversion of Yeast Mating Types III. Action of the Homothallism (HO) Gene in Cells Homozygous for the Mating Type Locus

Mating type interconversion in homothallic Saccharomyces cerevisiae has been studied in diploids homozygous for the mating type locus produced by sporulation of a/a/a/α and a/a/α/α tetraploid strains. Mating type switches have been analyzed by techniques including direct observation of cells for changes in α-factor sensitivity. Another method of following mating type switching exploits the observation that a/α cells exhibit polar budding and a/a and α/α cells exhibit medial budding.—These studies indicate the following: (1) The allele conferring the homothallic life cycle (HO) is dominant to the allele conferring the heterothallic life cycle (ho). (2) The action of the HO gene is controlled by the mating type locus—active in a/a and α/α cells but not in a/α cells. (3) The HO (or HO-controlled) gene product can act independently on two mating type alleles located on separate chromosomes in the same nucleus. (4) A switch in mating type is observed in pairs of cells, each of which has the same change.     

Physiological Effects of a and {alpha} Sexual Agglutination Substances on Mating Reaction in the Yeast Saccharomyces cerevisiae

The sex-specific glycoprotein agglutination substance, responsiblefor sexual agglutination, solubilized from the surface of haploidcells of a or a mating type by the autoclave method had thefollowing effects on mating reaction in Saccharomyces cerevisiae.Sexual agglutination was inhibited by the agglutination substanceof the opposite mating type in living cells as well as in heat-killedcells. Formation of zygotes was completely inhibited, when botha and a cells were treated with the agglutination substanceof the opposite mating type. The a and a agglutination substanceswere inactivated by cells of the opposite mating type, withthe degree of inactivation being greater for the former. Theenzyme responsible for the inactivation of a agglutination substanceseems to be carboxypeptidase Y. ¹ This paper is dedicated to the late Professor J. Ashida, KyotoUniversity. ² Present address: Department of Plant Pathology, Universityof California, Davis, CA. 95616, U.S.A. (Received November 1, 1982; Accepted January 19, 1983)     

Localization of the Mating Type Gene in Agaricus bisporus

The cultivated mushroom Agaricus bisporus is secondarily homothallic. Most basidia produce two basidiospores, each of which receives two of the four postmeiotic nuclei. Usually, the two packaged nuclei carry compatible mating types. Previous studies suggested that there may be only a single mating type locus in A. bisporus. In this study, we determined whether the mating type segregated as a single Mendelian determinant in a cross marked with 64 segregating molecular markers. To score mating types, each of the 52 homokaryotic offspring from this cross was paired with each of the two progenitor homokaryons. Compatible matings were identified by the formation of genetically stable heterokaryons which were verified by assay of restriction fragment length polymorphisms (RFLPs). Data for screening mycelial interactions on petri plates as well as fruit body formation were compared with the RFLP results. Mating types of 43 of the 52 homokaryotic offspring were determined on the basis of RFLP analysis. Our results indicate (i) there is a segregating mating type gene in A. bisporus, (ii) this mating type gene is on the largest linkage group (chromosome I), (iii) mycelial interactions on petri plates were associated with heterokaryon formation under selected conditions, (iv) fruit body formation was dependent upon the mating type gene, and (v) compatible mating types may not always be sufficient for fruiting.     

The Mating System in Saccharomyces

Many, but not all, Saccharomyces species are heterothallic.The mating types in heterothallic species are determined bytwo allelic genes. The mating-type genes occasionally mutatefrom one to the other. Vegetative cells of opposite mating typewere found in some single ascospore colonies. They show conjugationtubes, stimulated by the proximity of cells of the other matingtype. The cultures alao show zygotes, which on sporulation yieldplus(+) and minus(–) progenies. The zygotes bud off diploid vegetative cells which grow fasterthan the original haploid cells and so tend to replace them.If mutation occurs early, replacement is complete and the culturegives no mating reaction but sporulates. If it occurs late,the culture is a mixture of haploid cells giving a mating reactionand diploid cells that will sporulate.     

Mating Type Specific Inhibition of Gametic Differentiation of Chlamydomonas reinhardtii by Tunicamycin

The effect of tunicamycin, an inhibitor of glycosylation ofproteins, on the gametic differentiation of Chlamydomonas reinhardtiiwas studied. When mt⁺ cells were treated with tunicamycin duringgametogenesis, the acquisition of agglutinability on their flagellawas completely inhibited. However, no significant inhibitionwas observed when mt^– cells were treated with tunicamycinduring gametic induction. The agglutinability of the fully competentgametes of mt⁺ cells decreased sharply after about 4 hr of incubationwith tunicamycin and was lost completely after 8 hr. These resultsindicate that the gametic flagellar membrane of the mt⁺ cellmay acquire glycoproteins with tunicamycin sensitive sugar chains,the halflife of which is about 6 hr. (Received August 11, 1981; Accepted October 7, 1981)     

Mating pheromone-induced alteration of cell surface proteins in the heterobasidiomycetous yeast Tremella mesenterica.

Mating pheromone-induced alteration of the cell surface proteins of haploid cells, presumed to play crucial roles in the specific cell-cell interactions during sexual conjugation of Tremella mesenterica , was investigated. Exposed surface proteins were revealed by lactoperoxidase-catalyzed iodination in combination with polyacrylamide gel electrophoresis and autoradiography. From comparison of the molecular species of 125I-labeled surface proteins of the vegetative and the gamete (mating pheromone-treated) cells of the two compatible mating types (ab and AB), it was suggested that a striking change in cell surface structure occurs during the differentiation; although labeled protein species of the vegetative cells of the two mating types were indistinguishable, several new species, both mating type specific and nonspecific, appeared in the gamete cells. Turnover of the labeled proteins of the vegetative cells was negligible, whereas that of the gamete cells was rapid with release of low-molecular-weight labeled proteins in the medium. A role for the labeled surface proteins of the gamete cells in the cell-cell interactions during sexual conjugation was suggested by the following: the surface changes were induced by mating pheromone; the labeled proteins were preferentially localized on the surface of the mating tube; the labeled species appeared sequentially during the differentiation; and mating type-specific species were present in both mating types.     

Mating Types in Stentor coeruleus

SYNOPSIS. Conjugation in Stentor coeruleus was investigated, using a standardized culture technic which yielded large numbers of mating pairs within a single culture. Spontaneous bursts of selfing occurred during a definite interval in the development of a culture. Structurally distinct preconjugator cells appeared immediately before as well as during the initial stages of a burst of conjugation. Mating pairs were formed by the union of 2 preconjugators.
Mixing 8 stocks in all possible combinations of pairs and observing their subsequent response revealed they were separable into 2 complementary mating types. The majority of mating pairs formed in mixtures of stocks consisted of individuals of different mating types.
It is suggested that control of mating types in the ciliate order Heterotrichida may be of a somewhat different nature from that found in other ciliates.