COMPARATIVE ULTRASTRUCTURAL STUDIES OF SPERMATOGENESIS IN THE METZGERIALES (HEPATICAE). I. THE BLEPHAROPLAST OF PALLAVICINIA LYELLII

The blepharoplast in the young spermatid of Pallavicinia is similar to that of other hepatics in that it comprises a four-layered multilayered structure (MLS) and two staggered, dimorphic basal bodies. The spline, approximately 40 μm in length and extending through nearly two full gyres, comprises 20 parallel microtubules at its anterior end and narrows to 17 at the posterior limit of the subjacent lamellar strip (LS). Behind this, the spline shank, approximately 32 μm in length, is reduced to six tubules. The LS curves around the spermatid, following the anterior one-third of the first gyre of the spine, and is approximately 7.5 μm in length, the longest yet recorded for the bryophytes. It is spatulate in outline, equaling the width of the spline anteriorly but tapering steeply from the right-hand side behind the anterior basal body (ABB). It then extends posteriorly as a narrow strip beneath the left-hand margin of the spline. The basal bodies of the greatly staggered flagella are nonoverlapping and separated by a distance of about 4.4 μm. The subapical ABB and PBB measure (including the ventral triplet extensions and transition zones) 1.2 μm and 2.4 μm in length, respectively. A short, narrow aperture equaling one tubule-diameter in width is located in the spline directly beneath the ABB. The anterior mitochondrion is about 7 μm long and follows the outline of the overlying LS, while a cupshaped posterior mitochondrion is appressed to the plastid. Comparisons with other taxa indicate that major distinguishing features of metzgerialian blepharoplasts are highly staggered, nonoverlapping basal bodies, greatly elongate anterior mitochondria, and six-tubule shanks. Great differences between the spermatids suggest wide phylogenetic discontinuities between the genera of the Metzgeriales.     

STUDIES OF SPERMATOGENESIS IN THE HEPATICAE. IV. ON THE BLEPHAROPLAST OF BLASIA

Spermatogenesis in Blasia pusilla L. was reexamined with electron optics to help evaluate conflicting results of the two earlier light microscope studies of this species. The present micrographic resumé of spermatid transformation confirms Sharp's observation of centrosomes in very young spermatids and agrees with Woodburn's general account of spermatozoid maturation. Further, male gamete development in Blasia is shown to be closely comparable to that of Marchantia and Pellia. It is concluded that Sharp's report of blepharoplast development in Blasia by fragmentation and coalescence was based on anomalous plant material.     

ULTRASTRUCTURAL STUDIES OF SPERMATOGENESIS IN THE ANTHOCEROTALES. II. THE BLEPHAROPLAST AND ANTERIOR MITOCHONDRION IN PHAEOCEROS LAEVIS: LATER DEVELOPMENT

Chromatin condensation begins as the multilayered structure (MLS) in Phaeoceros reaches its maximally structured differentiation. As nuclear elongation and chromatin condensation proceed, the S_2–4 strata disappear, and the nuclear beak extends between the S₁ and the nearly spherical anterior mitochondrion. In a mature sperm the mitochondrion is elongate and lies completely anterior to the blunt front end of the nucleus. The 12 S₁ tubules extend over the anterior mitochondrion and nucleus, but their number becomes reduced to five at the level where the nucleus' midportion is constricted. The anterior ends of the S₁ tubules lie embedded in a rather conical osmiophilic crest. Flagellar insertion is restricted to the extreme anterior tip of the S₁ tubules. The locomotory apparatus in Phaeoceros is compared with that of other bryophytes.     

ULTRASTRUCTURAL STUDIES OF SPERMATOGENESIS IN THE ANTHOCEROTALES. I. THE BLEPHAROPLAST AND ANTERIOR MITOCHONDRION IN PHAEOCEROS LAEVIS: EARLY DEVELOPMENT

Electron microscopic examination of thin sections showed that the blepharoplast of a young spermatid of Phaeoceros consists of two side-by-side centrioles and an accumulation of osmiophilic, granular matrix at their proximal ends. Lying between these nearly parallel organelles is a dark-staining body that will later disappear at the onset of flagellogenesis. For a brief period the centrioles are oriented perpendicular to the nuclear surface so that the granular matrix at their proximal ends is confluent with the nuclear envelope; furthermore, the nucleoplasm immediately in front of the centrioles becomes densely staining. The multilayered structure (MLS) develops directly under the centrioles. It comprises a band of 12 microtubules (the S₁ stratum) and three lower strata (S_2–4) whose constitutent lamellae are oriented at an oblique angle to the S₁ axis. While the S₁ tubules grow rearward over the nucleus which forms a beak adjacent to the posterior end of the lamellar strata, the centrioles are transformed into basal bodies with the distal growth of the axonemes and the proximal growth of the central cartwheels and lowermost triplets. The proximal ends of the basal bodies and the S₁ tubules overlying the lamellar strata are invested with osmiophilic matrix that extends down to the S₂ layer and may temporarily occlude the lamellar plates. At the onset of nuclear elongation an anterior mitochondrion becomes situated close beneath the lamellar strata which extend laterally beyond the S₁ tubules.     

STUDIES OF SPERMATOGENESIS IN THE HEPATICAE V. BLEPHAROPLAST DEVELOPMENT IN MARCHANTIA POLYMORPHA

Coaxial centrioles and a microtubule organizing center (MTOC) constitute each centrosome in spermatid mother cells of Marchantia polymorpha. During cell division the centrosome separates at its midregion and the two centrioles undergo a planar rotation that brings them to lie somewhat staggered and nearly parallel with their proximal ends embedded in osmiophilic granular material similar in appearance to that of the MTOC. Microtubules of the multilayered structure (MLS) arise in this material below the posterior centriole and parallel to its long axis. The rotation of centrioles and the initiation of S₁ tubules below the posterior centriole determine polarity of the incipient blepharoplast. Lower MLS strata are formed under the anterior centriole by the compaction of granular, osmiophilic matrix. Formation and growth of S₂ vertical lamellae occur at the left front edge of the MLS in association with MTOC-like matrix localized near the cell membrane. The MLS enlarges to about 0.4 μm wide by 0.6 μm long and is ovoid in outline except for a short distal projection underlying the posterior centriole. Subsequently the lamellae are transformed into homogenous, osmiophilic matrix that contributes directly to the expansion of all MLS strata including microtubules. The stratum of lamellae is interpreted as a planar MTOC subject to morphogenetic control. Each of the four strata grows proximally while the tapering distal projection lengthens beneath the posterior basal body. Dense matrix above the MLS, apparently elaborated by the S₂ layer, is organized into cartwheel and triplet components of the basal bodies’ proximal extensions. Organization of triplet tubules proceeds from proximal to distal toward preexisting triplets. Osmiophilic matrix contributes to the formation of microtubule keels and osmiophilic crests and may serve as a cementing material that stabilizes the spatial relationships of blepharoplast components. After full expansion of the MLS’ lower strata, the S₂ layer is reorganized into lamellae. Flagellar growth in Marchantia is postulated to involve a process whereby subunits or their precursors are elaborated by the MLS, translocated to the distal end of the flagellum and incorporated into the axonemal tubules. When MLS microtubules elongate to form a long, narrow band, the distal half of the S₂ layer is again in the osmiophilic matrix state.     

INDUCED APOSPORY IN THE LIVERWORT BLASIA PUSILLA

Immature sporophytes of Blasia pusilla L. collected in the field were excised from the protective gametophytic tissues and cultured on a slightly modified Knop's agar substrate in microphytotrons. Under the experimental conditions the setae elongated and after 33½ to 6 weeks many began to give rise to from 1 to 20 or more aposporous outgrowths. These subsequently developed into young gametophytes. The apices were then cut off, sterilized, and grown on glucose-mineral agar in aseptic culture. The resulting gametophytes were similar to haploid plants derived from spores in pattern and rate of growth, and in possession of rhizoids, ventral scales, lateral lobes, auricles, and stellate and discoid gemmae. They produced archegonia but no antheridia. The chromosome number of the aposporous plants was 18 in contrast to the normal haploid number of 9.     

中华双腔吸虫精子发生的超微结构研究

应用透射电镜技术,研究中华双腔吸虫的精子发生,并与其它复殖吸虫进行比较,提出了复殖吸虫精子发生的一般过程,结果显示它与大多数复殖吸虫精子发生的超微结构相似,原始的精原细胞经过次有丝分裂,两次减数分裂成为精细胞,它经过分化,形态变化后成为成熟精子,精子形成共分为六个阶段。其中形成共分为六个阶段,其中有以下首次报道的特征,（１）中央胞持区的生长速度在开始时比鞭毛裂快;（２）在鞭毛与中央胞质区融合前,线     

SPERMATOGENESIS IN COLEOCHAETE PULVINATA (CHAROPHYCEAE): EARLY BLEPHAROPLAST DEVELOPMENT

Transmission electron microscopy of serial thin sections was used to reconstruct several early developmental stages of the blepharoplast in Coleochaete pulvinata spermatids. These were compared to published studies of blepharoplast development in Charales and the closest relatives of charophycean green algae among embryophytes, i.e., hornworts and liverworts. Bicentriolar centrosomes such as occur in bryophytes and fern allies were not observed in Coleochaete. Centriole replication in C. pulvinata was orthogonal as in Charales. The resulting two daughter centrioles were oriented perpendicularly and joined proximally by electron-dense material. Their orthogonal relationship was maintained throughout blepharoplast development by a massive, banded connective which appeared early. In spermatids of hornworts and liverworts, a multilayered structure (MLS) develops in association with two centrioles destined to become flagellar basal bodies. When the MLS of these lower land plants is sectioned at right angles to the long axis of the microtubular layer, the MLS is observed to lie beneath cross sections of both centrioles. In contrast, when developing MLSs of C. pulvinata and Charales are similarly sectioned, they occur beside a cross section of just one of the two centrioles. In C. pulvinata (as in other charophytes), MLS lamellae are oriented at a 90-degree angle to the long axis of the S₁ microtubules from the beginning. This contrasts with the 40–45 degree angle between the MLS lamellae and S₁ microtubules universally reported for archegoniates. In early C. pulvinata spermatids, spline microtubules are closely associated with an anterior mitochondrion having a low stromal density and few cristae. An anterior mitochondrion is typically associated with blepharoplast development in hornworts and liverworts, but has not previously been reported to occur in Coleochaete or any other charophycean alga. In Coleochaete, as in hornworts and liverworts, but unlike Charales, structure of mature blepharoplasts reflects early blepharoplast ontogeny. Very little change in positional relationships among blepharoplast components (flagella, connective, MLS) occurs during development. These character-state differences are of importance in cladistic analyses of charophycean algae and lower land plants.     

褶纹冠蚌精子发生的研究

光镜和透射电镜研究结果表明：褶纹冠蚌精子发生是非同步的,精子发生经历了一系列重要的形态和结构变化,主要包括：核逐步延长、染色质浓缩、线粒体逐渐发达与融合、胞质消除以及鞭毛的形成。精原细胞胞质中含有许多致密的轴纤丝,它们后来形成鞭毛轴丝。精母细胞质中含有线粒体、中心粒、内质网和电子透明的囊泡。精细胞分化为４个时期。成熟精子属原始类型,由头部、中段和尾部三部分组成。多核结构和细胞间桥自始至终存在于精子     

若干铁杉属植物核型的比较研究

本文首次报道了我国特产的重点保护植物南方铁杉的核型,全由中部和近中部着丝点染色体构成,核型公式为K(2n)=2x=24=20m+4sm,属“ 2A”类型。染色体的相对长度组成为2n=24=12M_2+10M_1+2S。通过比较。发现东亚的南方铁杉的核型与台湾铁杉甚为相似而略具进化的趋势,但北美东部的卡罗来纳铁杉的核型比它们进化得多。本文支持Florin认为铁杉属至少在早第三纪存在一条从欧亚大陆经过白令海峡到达北美洲的迁移路线的意见。     

台湾东风螺精子发生和精子形态的超微结构研究

透射电镜研究结果表明,台湾东风螺(Babylonia formosae~**)精子形成过程中经历了一系列重大的形态变化,主要有核逐步拉长、染色质浓缩、顶体形成、线粒体逐渐发达与融合以及中心粒演变为轴丝等过程。其中精细胞分化可分为6个时期。成熟精子的外形呈发丝状,由头部和尾鞭两大部分组成,头部包括顶体复合体和核,尾鞭可分为中段、主段和末段。精子的形态及功能与软体动物的系统发育有密切关系。本文还就台湾东风螺精子形成过程和形态与其它前鳃类作了比较。     

ULTRASTRUCTURAL STUDIES ON SPHAEROPLEA ANNULINA (CHLOROPHYCEAE). II. SPERMATOGENESIS AND MALE GAMETE STRUCTURE1,2

The development and ultrastructure of the male gamete of Sphaeroplea annulina (Roth) Agardh have been investigated. Multiple mitoses each associated with phycoplast microtubules occur as a result of nitrogen deficiency in the culture medium. A regular cleavage of the cytoplasm delineated by microtubules then occurs, resulting in many young male gametes. During maturation the gametes are retained within a vacuolar envelope. Maturation entails reduction in nuclear size and chromatin condensation, loss of chloroplast thylakoids, endoplasmic reticulum and Golgi apparatus. The apical region where the two flagella are inserted consists of an apical cone and fibrous connections which lie distal to the basal bodies. The study supports the suggestion put forward in a previous paper: namely that the genus Sphaeroplea be retained in a separate order the Sphaeropleales.     

STUDIES OF SPERMATOGENESIS IN THE HEPATICAE : II. Blepharoplast Structure in the Spermatid of Marchantia

The blepharoplast in a young, developing spermatid of Marchantia polymorpha, is a composite structure consisting of two basal bodies and a subjacent narrow band of axonemal-type tubules that we have termed the "spline." For most of its length, the spline consists of six long parallel tubules that nearly encircle the cell. The spline anterior is asymmetrically widened for about 2 µ by shorter tubules of the same kind. The lateral displacement of three long, adjacent marginal tubules by three short intervening tubules at the spline tip produces a long narrow aperture. Distally, the aperture is closed by the convergence of the displaced tubules with another trio of long tubules. Together, these form the six-membered cell-encircling portion. The expanded spline anterior has, at this stage of development, the four-layered (Vierergruppe) structure, of which the aforementioned tubules constitute the uppermost layer. The lower three strata consist of diagonal fins, elongated chambers, and fine tubules, respectively. The two flagellar bases lie close above the spline tip—one slightly anterior to the other—and diverge unequally from the spline axis. A few triplets extend proximally from the basal bodies, but do not connect with the spline. The anterior basal body is longer than the posterior one.     

东方扁虾精子发生的超微结构

应用电镜技术研究了东方扁虾（Thenus orientalis)精子发生的全过程,精原细胞呈椭圆形,其染色质分布较均匀,线粒体集中于细胞一端形成“线粒体区”。初级精母细胞较大,染色质凝聚成块,次级精母细胞核质间常出现大的囊泡,胞质内囊泡丰富而线粒体数量却明显减少,早期精细胞核发生极化、解聚,部分胞质被抛弃。中期精细胞外观呈金字塔形,分为三区;正在形成的顶体位于塔顶,核位于塔基部,居间的细胞质基质内富含膜复合物,后期精细胞顶体进一步分化。形成顶体帽和内、外顶体物质等三个结构组份。成熟精子核呈盘状或碗状,具有5-6条内部充满微管的辐射臂。     

STUDIES OF SPERMATOGENESIS IN THE HEPATICAE : I. Ultrastructure of the Vierergruppe in Marchantia

Spermatids of the liverwort Marchantia polymorpha were shown by analysis of thin-sections to contain a four-layered organelle, the Vierergruppe, lying between the flagellar bases above and a subjacent mitochondrial body. The uppermost layer consists of parallel tubules structurally similar to those of the axoneme. Some of the tubules extend beyond the four-layered region to form a long ribbon-like appendage. The second layer consists of low, vertical, membranous fins connected by numerous short links to the tubules above. The third layer, limited above and below by two horizontal membranes, consists of vertical partitions, apparently continuous with the fins. The fourth and lowermost layer consists of narrow parallel tubules aligned beneath alternate partitions. The long axes of the lower three layers are parallel to each other and lie at an angle of 48° to the tubule axis of the uppermost stratum. A graphic representation of a three-dimensional scale model interpreting organelle structure is given. The Vierergruppe supersedes Dreiergruppe interpretation in most if not all of the bryophytes studied to date.     

梨胶锈菌性孢子和锈孢子阶段吸器的超微结构研究

本文对梨胶锈菌性子期和锈子期菌丝吸器的形成方式、吸器及其与寄主细胞界面的超微结构进行了研究。观察结果表明：梨胶锈菌性子期和锈子期寄主胞间菌丝吸器的形成方式有两种：一种是由寄主胞间菌丝直接形成吸器;另一种是由寄主胞间菌丝先形成吸器母细胞,然后由吸器母细胞形成吸器。吸器在开始形成时只是一个乳头状的侵入楔,以后逐渐形成囊状、镰刀状、指状及其它不规则形状的吸器。多数吸器分化为颈和吸器主体两部分,在颈部及部分吸器主体外有一个由类似寄主细胞壁物质形成的领圈。吸器内部的超微结构与寄主胞间菌丝基本相同,但吸器壁比胞间菌丝或吸器母细胞的壁薄。吸器鞘的厚度随着吸器伸长膨大而逐渐增厚。     

金丝猴(RHINOPITHECUS)肌肉系统某些特征的比较研究

本文对金丝猴与其他灵长类之间和三种金丝猴之间特征不同的56条肌作了比较研究。结果表明:三种金丝猴的肌肉系统存在一些差异。纠正了Patterson(1942)对一例川金丝猴的一些错误观察记录。在金丝猴属的肌学方面除与猴超科共有的大部分特征外,还具有与类人猿和人相似的特征。在猴类中,金丝猴的肌肉系统更多地与叶猴相似,其中一些特征较叶猴更为进化。从进化观点看,金丝猴的肌学特征似介于叶猴与类人猿之间,故它们比其他猴超科动物更为进化。     

细鳞鱼精巢超微结构和精子发生

细鳞鱼Brachymystax lenok(Pallas)精巢为叶型;支持细胞(Sertoli cell)和Leydig细胞具有典型内分泌细胞的一些结构特征;A型精原细胞的细胞器是区域性分布,精原细胞线粒体的发育与拟染色质 (chromatoid bodies)有关;生精细胞(spermatogenic cell)核膜孔由均匀排布最终演变为区域性聚集。重复注射绒毛膜促性腺激素(hCG)可促进雄鱼性成熟;精子质量受到多种因素的影响。     

ENDOCRINOLOGICAL STUDIES ON SPERMATOGENESIS IN THE SILKWORM, BOMBYX MORI L.

When embryonic testes 1 or 2 days before hatching were transplanted into 5 kinds of hosts (5th instar larvae, “fresh” pupae just after pupation, isolated pupal abdomens and 3-day-old pupae with and without their original corpora allata), the testes transplanted into 5th instar larvae grew most conspicuously and spermiogenesis began in many cysts. A few spermatidal cysts were observed in the testes transplanted into fresh pupae. No signs of maturation were observed in the testes transplanted into other hosts. It is concluded that prothoracic gland hormone might be responsible for the precocious maturation of young testes. On the other hand, the initiation of spermiogenesis was delayed, in comparing with controls, in the 3rd instar larval testes as follows: the testes transplanted into 3-day-old pupae, the testes transplanted into isolated pupal abdomens together with adult corpora allata and the testis into which corpus allatum of a 3rd instar larva was inserted. It is concluded that corpora allata hormone exerts an inhibitory effect on spermatogenesis.     

大叶杨组组间杂交花粉－柱头相互作用的超微结构研究

以大叶杨为母本,分别与小叶杨、欧洲黑杨、响叶杨进行人工杂交,并以大叶杨×大叶杨为对照,观察其花粉与柱头相互作用的超微结构变化。结果表明,大叶杨柱头细胞在授粉前表现生理活跃,含丰富的细胞器,壁外被含分支通道的角质层。接受大叶杨及欧洲黑杨花粉的柱头细胞内部仍有丰富的细胞器,膜结构保存完好。接受小叶杨及响叶杨花粉的柱头细胞衰亡较快,授粉部位沉积厚的胼胝质,细胞内部液泡化,膜结构逐渐消失,细胞质电子密度加大。欧洲黑杨花粉行为与大叶杨花粉行为相似,花粉能迅速萌发,并以短管形式穿入柱头,异常行为罕见。小叶杨及响叶杨花粉萌发后只有半数花粉管能以短管形式进入柱头,其中部分管内沉积胼胝质,另半数花粉管在柱头上表现各种异常行为——扭曲、爬行、肿胀、提前破裂释放内容物及先端沉积胼胝质。由各种花粉在大叶杨柱头上的行为和大叶杨柱头对各种授粉的反应判断,与大叶杨杂交亲和力在柱头阶段表现由强至弱依次是欧洲黑杨、小叶杨、响叶杨。