Carrier of reduced sulfur is a possible role for thiotaurine in symbiotic species from hydrothermal vents with thiotrophic symbionts

Experiments supporting the possible role of the free sulfur-containing amino acid thiotaurine, as a transport and storage compound for sulfide in invertebrates with thiotrophic symbionts are described. The free-living chemotrophic sulfur-oxidising bacterium, Thiobacillus hydrothermalis (strain DSMZ 7121), was used as a model for the symbionts as the actual symbionts have not been obtained in culture.Thiotaurine contains two sulfur atoms, namely the inner sulfone and the outer sulfane sulfur; the latter presents a potential source of reducing equivalents for the symbiont. Nevertheless, we observed no oxidation of thiotaurine when this compound was added to a culture of T. hydrothermalis pre-grown on sulfide. In contrast, when thiotaurine was added to the culture together with an extract of the trophosome of a vestimentiferan tubeworm from the Manus basin, we observed that thiotaurine was oxidised to hypotaurine with concomitant acidification and formation of bacterial biomass. Thus, the trophosome contains an unknown catalytic factor. We suggest that thiotaurine requires reduction prior to oxidation by T. hydrothermalisand that the host may catalyse the conversion of thiotaurine through the glutathione redox couple. This way, the host can accurately control energy delivery (as reduced sulfur) to the symbionts and can therefore control their symbiont biomass.     

The evolution of conspicuous facultative mimicry in octopuses: an example of secondary adaptation?

The ‘Mimic Octopus’Thaumoctopus mimicus Norman & Hochberg, 2005 exhibits a conspicuous primary defence mechanism (high‐contrast colour pattern during ‘flatfish swimming’) that may involve facultative imperfect mimicry of conspicuous and/or inconspicuous models, both toxic and non‐toxic (Soleidae and Bothidae). Here, we examine relationships between behavioural and morphological elements of conspicuous flatfish swimming in extant octopodids (Cephalopoda: Octopodidae), and reconstructed ancestral states, to examine potential influences on the evolution of this rare defence mechanism. We address the order of trait distribution to explore whether conspicuous flatfish swimming may be an exaptation that usurps a previously evolved form of locomotion for a new purpose. Contrary to our predictions, based on the relationships we examined, flatfish swimming appears to have evolved concurrently with extremely long arms, in a clade of sand‐dwelling species. The conspicuous body colour pattern displayed by swimming T. mimicus may represent a secondary adaptation potentially allowing for mimicry of a toxic sole, improved disruptive coloration, and/or aposematic coloration. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2010, 101 , 68–77.     

Euspermatozoa and paraspermatozoa in the volutid gastropod Odontocymbiola magellanica,Patagonia, Argentina,Southwestern Atlantic Ocean

Giménez J. 2010. Euspermatozoa and paraspermatozoa in the volutid gastropod Odontocymbiola magellanica, Patagonia, Argentina, Southwestern Atlantic Ocean. —Acta Zoologica (Stockholm) 92 : 355–362. The ultrastructure of mature spermatozoa and paraspermatozoa of Odontocymbiola magellanica is investigated. Euspermatozoa consist of: (1) a tall, conical acrosomal vesicle (with a short basal invagination, constricted anteriorly); (2) a rod‐shaped, solid and highly electron‐dense nucleus; (3) an elongate midpiece consisting of the axoneme sheathed by helical mitochondrial elements each exhibiting a dense U‐shaped outer layer; (4) an elongate glycogen piece; (5) a dense annulus at the junction of the midpiece and glycogen piece; and (6) a short free‐tail region. Paraspermatozoa of O. magellanica are vermiform and dimorphic. First type contain approximately 14–17 axonemes (arranged peripherally and interspersed with microtubules) and numerous oblong dense vesicles, numerous less dense (round) vesicles, and scattered mitochondria; the second type contains 38–45 axonemes peripherally arranged and closer to the core region of the cell and occasional mitochondria. Most of the euspermatozoal features of O. magellanica are also observed in many neotaenioglossans and neogastropods. However, the U‐shaped outer layer of each mitochondrial element has only been previously reported in the Volutidae subfamily Zidoniinae. It is now reported here in the subfamily Odontocimbiolinae and may prove to be a diagnostic feature of the Volutidae family.     

Ultrastructure of euspermatozoa and paraspermatozoa in the volutid snail <Emphasis Type="Italic">Adelomelon ancilla</Emphasis> (Mollusca: Caenogastropoda)

The ultrastructure of the euspermatozoa and the paraspermatozoa is investigated in Adelomelon ancilla, through histological section observed by transmission electron microscopy. Euspermatozoa of A. ancilla consists of: (1) a conical acrosomal vesicle (with a short basal invagination, constricted anteriorly) which is flattened at the apex and associated with an axial rod, a centrally perforated basal plate and a short accessory membrane, (2) a rod-shaped, solid and highly electron-dense nucleus (with a short basal fossa containing a centriolar complex and a initial portion of a 9 + 2 axoneme), (3) an elongate midpiece consisting of the axoneme sheathed by 5–6 helical mitochondrial elements each exhibiting a dense U-shaped outer layer, (4) an elongate glycogen piece (where the axoneme is sheathed by nine tracts of glycogen granules), (5) a dense annulus at the junction of the midpiece and glycogen piece, and (6) a short free tail region (where the axoneme is surrounded only by plasma membrane). We observed a parasperm in A. ancilla. This is vermiform in shape and is composed of multiple axonemes and extensive cytoplasm with numerous vesicles, and mitochondria are scattered inside the axonemes. Sperm of A. ancilla is characterized by the euspermatozoa type 2 and the paraspermatozoa morphology belongs to type 5. The U shaped electrodense mitochondrial element in the midpiece of the eusperm and the constriction in the acrosomal vesicle present in A. ancilla are exclusive. We suggest that these characteristics could have taxonomic importance, because these was observed in other volutids and have not been observed in the rest of caenogastropods studies. We consider that the morphology of paraspermatozoa in A. ancilla corresponds to the “lancet” type.     

Sperm ultrastructure of the spider crab Maja brachydactyla (Decapoda: Brachyura)

This study describes the morphology of the sperm cell of Maja brachydactyla, with emphasis on localizing actin and tubulin. The spermatozoon of M. brachydactyla is similar in appearance and organization to other brachyuran spermatozoa. The spermatozoon is a globular cell composed of a central acrosome, which is surrounded by a thin layer of cytoplasm and a cup‐shaped nucleus with four radiating lateral arms. The acrosome is a subspheroidal vesicle composed of three concentric zones surrounded by a capsule. The acrosome is apically covered by an operculum. The perforatorium penetrates the center of the acrosome and has granular material partially composed of actin. The cytoplasm contains one centriole in the subacrosomal region. A cytoplasmic ring encircles the acrosome in the subapical region of the cell and contains the structures‐organelles complex (SO‐complex), which is composed of a membrane system, mitochondria with few cristae, and microtubules. In the nucleus, slightly condensed chromatin extends along the lateral arms, in which no microtubules have been observed. Chromatin fibers aggregate in certain areas and are often associated with the SO‐complex. During the acrosomal reaction, the acrosome could provide support for the penetration of the sperm nucleus, the SO‐complex could serve as an anchor point for chromatin, and the lateral arms could play an important role triggering the acrosomal reaction, while slightly decondensed chromatin may be necessary for the deformation of the nucleus. J. Morphol., 2010. © 2009 Wiley‐Liss, Inc.     

Ultrastructure of sperm development in the free-living marine nematode Metachromadora itoi (Chromadoria, Desmodorida)

The spermatogenesis of the free‐living marine nematode Metachromadora itoi was studied with electron microscopy. Spermatocytes and early spermatids have no cytoplasmic components specific for nematodes, i.e. membranous organelles (MO) and fibrous bodies (FB). The late spermatids are subdivided into the residual body and the main cell body with a centrally located nucleus devoid of a nuclear envelope. A pair of 9 × 2 centrioles is associated with the nuclei of spermatids and spermatozoa. The nucleus of the mature spermatid is surrounded by a thick mass of radially arranged FB delimited externally by a discontinuous layer of mitochondria, which underlie a thin ectoplasm. Sperm development is accompanied by transfer of FB matter through the mitochondrion layer into the ectoplasm. The immature spermatozoa from the testis have the centrally located nucleus surrounded by a transparent halo with remnants of FB. The halo is delimited by a sphere of mitochondria that underlie the thick fibrous ectoplasm, a derivative of the FB. In the mature spermatozoa the ectoplasm is transformed into the prominent unpolarized pseudopod. The central nucleus is surrounded by a transparent halo and a sphere of mitochondria, which underlie the pseudopod. MO were not found throughout spermatogenesis. In general, spermatogenesis in M. itoi differs from that observed in many nematodes but resembles in some details the sperm development in some chromadorid and tylenchomorph nematodes. The phylogenetic importance of this sperm development is discussed.     

Rapid commencement of ecosystem recovery following aerial baiting on sub‐Antarctic Macquarie Island

Introduced rabbits have severely impacted the terrestrial ecosystem of sub‐Antarctic Macquarie Island. Here we describe first observations of rapid recovery of an important plant species following the commencement of a vertebrate pest eradication plan. The tussock grass Poa foliosa, a major component of the Macquarie Island landscape, has been severely impacted by rabbit grazing with large‐scale reductions in cover across the island observed at times over the last 50 years. Preliminary aerial baiting for rabbits and rodents commenced in winter 2010, and within 6 months, we observed substantial regrowth of tussock grass. The rapid re‐emergence of this grass over such a short time period following localised removal of rabbits has positive implications for the island’s recovery and provides insight for restoration monitoring.     

The arrangement of chromosomes in nuclei of sperm from plethodontid salamanders

Plethodontid salamanders have n = 13 or 14 large metacentric or sub-metacentric chromosomes. Sperm nuclei from Plethodon cinereus measure 72×1 m. The nucleoprotein of spermatids is at first finely granular. In elongate spermatids it clumps into larger granules, which then fuse to form the compact nucleoprotein of the mature sperm. The nuclei of mature sperm are negatively birefringent with respect to their length. — ³H RNA complementary to high-density satellite DNA of centromeric heterochromatin in P. cinereus has been hybridized in-situ to spermatids and sperm, and its site of binding to these cells has been examined by autoradiography. Labelling of round spermatid nuclei is localized in a single patch. Elongate spermatid nuclei are labelled only over the rear quarter of the nucleus. Label over the nuclei of mature sperm is localized in a region extending 10–20 m forwards from the rear of the nucleus. — In P. cinereus the ribosomal genes are located near the centromere on the short arm of chromosome 7. ³H ribosomal RNA hybridizes to a single patch in round spermatid nuclei. Elongate spermatid nuclei show label over a short segment of the rear half of the nucleus. In spermatids nearing maturity the labelled region is never more than 20 m long. — These results indicate that in P. cinereus each chromosome is arranged in a U formation with its centromere at the base of the sperm nucleus, and its arms extended forwards along the length of the nucleus. — Among plethodontids, increase in C value and corresponding increase in chromosome size is accompanied by increase in the length rather than the width of the sperm nucleus. — ³H ribosomal RNA hybridizes to a short segment in spermatid and sperm nuclei from Xenopus and Triturus. In these animals, the position of the labelled segment varies from sperm to sperm.     

Ultrastructure of spermiogenesis in the American alligator,Alligator mississippiensis (Reptilia,Crocodylia, Alligatoridae)

Testicular samples were collected to describe the ultrastructure of spermiogenisis in Alligator mississipiensis (American Alligator). Spermiogenesis commences with an acrosome vesicle forming from Golgi transport vesicles. An acrosome granule forms during vesicle contact with the nucleus, and remains posterior until mid to late elongation when it diffuses uniformly throughout the acrosomal lumen. The nucleus has uniform diffuse chromatin with small indices of heterochromatin, and the condensation of DNA is granular. The subacrosome space develops early, enlarges during elongation, and accumulates a thick layer of dark staining granules. Once the acrosome has completed its development, the nucleus of the early elongating spermatid becomes associated with the cell membrane flattening the acrosome vesicle on the apical surface of the nucleus, which aids in the migration of the acrosomal shoulders laterally. One endonuclear canal is present where the perforatorium resides. A prominent longitudinal manchette is associated with the nuclei of late elongating spermatids, and less numerous circular microtubules are observed close to the acrosome complex. The microtubule doublets of the midpiece axoneme are surrounded by a layer of dense staining granular material. The mitochondria of the midpiece abut the proximal centriole resulting in a very short neck region, and possess tubular cristae internally and concentric layers of cristae superficially. A fibrous sheath surrounds only the axoneme of the principal piece. Characters not previously described during spermiogenesis in any other amniote are observed and include (1) an endoplasmic reticulum cap during early acrosome development, (2) a concentric ring of endoplasmic reticulum around the nucleus of early to middle elongating spermatids, (3) a band of endoplasmic reticulum around the acrosome complex of late developing elongate spermatids, and (4) midpiece mitochondria that have both tubular and concentric layers of cristae. J. Morphol., 2010. © 2010 Wiley‐Liss, Inc.     

CONFERENCE REPORT

ABSTRACT

Sperm whale Physeter macrocephalus L. clicks have been studied for nearly fifty years, during which time great efforts have been made to understand the functions and production mechanisms of this sound. Other than clicks, sperm whales may also produce low intensity sounds arranged in short sequences, named trumpets, which have been recorded occasionally in the past by few groups of researchers. Sperm whale recordings collected in the Mediterranean Sea with a towed array and digital tags were used to describe the temporal and spectral characteristics of trumpets. This sound is made of a series of repeated units, around 0.2 s long, arranged in short sequences lasting between 0.6 s to 3.5 s. Each of these units comprises an amplitude modulated tonal waveform with a complex harmonic structure, and a spectrum composed of a low frequency component at 500 Hz and a mid-frequency component at 3 kHz. The apparent source level could be estimated for one of the trumpets and was estimated to be 172 dB_pp re: 1μPa at lm with energy flux density of 147 dB re: 1μ Pa²s.     

Sperm structure of Mecoptera and Siphonaptera (Insecta) and the phylogenetic position of<Emphasis Type="Italic"> Boreus hyemalis</Emphasis>

Sperm ultrastructure has been studied in three species of the taxa Mecoptera and Siphonaptera. The spermatozoon of the scorpion fly Panorpa germanica shows an apical bilayered acrosome, a helicoidal nucleus, a centriolar region and a 9+2 flagellar axoneme helicoidally arranged around a long mitochondrial derivative. A second mitochondrial derivative is very short and present only in the centriolar region. A single accessory body is present and it is clearly formed as a prolongation of the centriole adjunct material. Two lateral lamellae run parallel to the nucleus. The snow fly Boreus hyemalis has a conventional sperm structure and shows a bilayered acrosome, a long nucleus, a centriolar region, two mitochondrial derivatives and two accessory bodies. The axoneme is of the 9+2 type and is flattened at the tail tip. Both P. germanica and B. hyemalis have two longitudinal extra-axonemal rods and have a glycocalyx consisting of longitudinal parallel ridges or filaments. The spermatozoon of the flea Ctenocephalides canis has a long apical bilayered acrosome, a nucleus, a centriolar region, a 9+2 axoneme wound around two unequally sized mitochondrial derivatives, and two triangular accessory bodies. In the posterior tail end the flagellar axoneme disorganises and a few microtubular doublets run helicoidally around the remnant mitochondrial derivative. The glycocalyx consists of fine transverse striations. In all three species, the posterior tail tip is characterised by a dense matrix embedding the disorganised axoneme. From this comparative analysis of the sperm structure it is concluded that Mecoptera, as traditionally defined, is monophyletic and that B. hyemalis is a member of Mecoptera rather than of Siphonaptera.     

Sperm ultrastructure in honeycomb (foam) oysters (Mollusca,Bivalvia, Gryphaeidae,Pycnodontinae): comparison with other Ostreoidea and taxonomic implications

Sperm ultrastructural features of the honeycomb (foam) oysters Hyotissa hyotis, H. sinensis, and H. mcgintyi (Gryphaeidae) are described and compared with other Ostreoidea and more generally with other pteriomorphian Bivalvia. Spermatozoa of H. sinensis and H. mcgintyi (the type species of Parahyotissa Harry 1985) exhibit (1) a broad, low‐conical acrosomal vesicle; (2) subacrosomal material (very electron‐dense granular material and an almost electron‐lucent axial rod); (3) a spheroidal nucleus with a wide anterior invagination (filled with subacrosomal components); (4) a midpiece composed of four spherical mitochondria surrounding a pair of centrioles (rootlet associated with proximal centriole); and (5) a flagellum. Sperm of Hyotissa hyotis (type species of Hyotissa Stenzel 1971) differ markedly from those of H. sinensis and H. mcgintyi, in having (1) a conical acrosomal vesicle showing coarse granular texture anteriorly; (2) a very electron‐dense axial rod; (3) a barrel‐shaped nucleus with a long, narrow anterior invagination (filled with both subacrosomal components) and a basal invagination partly housing the proximal centriole; and (4) five midpiece mitochondria and no proximal centriolar rootlet. Results indicate that H. sinensis should be relocated to another genus, possibly a revised genus Parahyotissa, and also show that the sperm of H. sinensis and H. mcgintyi show many similarities to those of the Ostreidae, with the exception that the ‘axial rod’ component of the subacrosomal material is less electron‐dense than the surrounding substance (more dense in Ostreidae, as in H. hyotis). No family defining sperm features of the Gryphaeidae can be identified.     

Isolation and Characterization of Thermophilic Bacteria from Gavmesh Goli Hot Spring in Sabalan Geothermal Field,Iran: Thermomonas hydrothermalis and Bacillus altitudinis Isolates as a Potential Source of Thermostable Protease

Abstract

Thermophilic bacteria have attracted great attention due to their ability to produce thermostable enzymes. The aim of this study was the isolation and characterization of thermophilic bacteria from Gavmesh Goli hot spring in Sareyn, North West of Iran. Of 10 water samples collected, 36 thermophilic bacteria were obtained. The thermophilic bacteria were tested for their ability to produce hydrolase enzymes. All the isolates were potentially protease producers. Lipase, DNase, and amylase activities were confirmed in 34 (94.4%), 8 (22.2%), and 3 (8.3%) isolates, respectively. Five isolates with higher levels of enzyme activity were selected for further studies. Morphological, biochemical, and molecular analysis by 16S rRNA gene sequencing revealed that four isolates (DH15, DH16, DH20, and DH29) could be identified as Thermomonas hydrothermalis and one (PA10) Bacillus altitudinis. The protease produced by these isolates was optimally active at 50–55?°C, pH 8–8.5, and 0–0.5?M NaCl. In this first time study, we isolated T. hydrothermalis and B. altitudinis from Iranian hot springs and demonstrated the characteristics of T. hydrothermalis protease. Accordingly, due to the valuable potential of these bacteria such as the production of protease with high temperature and pH stability, these isolates can be introduced as promising candidates for industrial applications.     

Between‐male variation in sperm size,velocity and longevity in sand martins Riparia riparia

Sperm mobility is known to be an important determinant of a male's sperm competitive ability. Although more debated, sperm length and its relation to sperm swimming ability has also been proposed to determine a male's fertilisation potential. Furthermore, both mobility and length may covary with a male's phenotype, either positively (the phenotype‐linked fertility hypothesis) or negatively if, for instance, low‐quality males have less access to females but invest more in sperm production. Using dummy females, we collected sperm samples from wild sand martins Riparia raparia males. We investigated the relationship between sperm length and sperm swimming speed as measured by sperm straight line velocity (VSL), and determined whether sperm traits are correlated with male body size and condition. We found that total sperm length is repeatable within‐ejaculate and shows substantial inter‐male variation. Sperm length was associated with sperm velocity: males with short sperm have sperm that swim initially faster but die sooner, whereas males with longer sperm have sperm that swim more slowly but for a longer time. Smaller males produced sperm with higher overall velocity. This correlation between male size and sperm behaviour may reflect alternative fertilisation strategies where small males having less mating opportunities invest more in sperm competitive ability. The existence of such alternative strategies would participate in maintaining variation in sperm length and velocity in this species.     

The male reproductive system,sperm, and spermatophores of the primitive,hermaphroditic, remipede crustacean Speleonectess benjamini

Summary

Speleonectes benjamini, a species of the primitive crustacean class Remipedia, is a simultaneous hermaphrodite. The male reproductive tract consists of paired testes and vas deferens. Sperm have an ovoid nucleus, acrosome, and a flagellum with a 9 + 2 microtubular arrangement. The spermatophores contain at least three sperm.     

Sperm ultrastructure in Bathypolypus bairdii and B. sponsalis (Cephalopoda: Octopoda)

A morphological comparison of the spermatozoa of the octopods Bathypolypus bairdii and B. sponsalis has been carried out by electron microscopy. Although the mature spermatozoon of B. bairdii is longer and thinner than that of B. sponsalis, its general ultrastructure is similar except for some minor differences. Their characteristic acrosomes, described here for the first time, consist of a periodically banded cone surrounded by a double helix whose arrangement has been defined by a numeric expression. The plasma membrane of sponsalis that surrounds the acrosome has many projections filled with abundant granular cytoplasm, which appears as a star‐shaped acrosome in cross‐section. The mitochondrial sheath contains 9–11 mitochondria in bairdii but only 9 in sponsalis. A comparison with other Octopodidae shows that the nucleus of both species is the largest ever seen. Our results support the capability of sperm morphology to discriminate between species and could even discern at higher taxonomic levels. J. Morphol., 2010. © 2009 Wiley‐Liss, Inc.     

Confirmation that Thiobacillus halophilus and Thiobacillus hydrothermalis are distinct species within the γ-subclass of the Proteobacteria

Thiobacillus halophilus and Thiobacillus hydrothermalis share 98.7% similarity in 16S rRNA sequence, possess similar gross DNA composition (64.2 and 67.4 mol% G+C values, respectively), and have similar physiological properties. While this might have indicated that they were strains of a single species, DNA-DNA hybridization between the type strains of the two species showed only 59% hybridization, indicating the organisms to be different at the species level. Thiobacillus neapolitanus is the phylogenetically nearest neighbour of T. halophilus and T. hydrothermalis (91.6–92.1% similarity in 16S rRNA sequence) and is the only other Thiobacillus in the γ-subclass of the Proteobacteria that can be regarded as exclusively related to these two species. The 16S rRNA gene sequences of these three species are so different from those of the other thiobacilli in the γ-subclass that they justify recognition as a distinct phyletic group. Their comparative properties are summarized. Received: 23 February 1998 / Accepted: 23 April 1998     

Quantitative cytology of the sperm cells of Brassica campestris and B. oleracea

Pollen grains of Brassica campestris L. var. acephala DC and B. oleracea L. were serially sectioned and examined using transmission electron microscopy to determine the three-dimensional organization of sperm cells within the microgametophyte and the quantity of membrane-bound organelles occurring within each cell. Sperm cells occur in pairs within each pollen grain, but are dimorphic, differing in size, morphology and mitochondrial content. The larger of the two sperm cells (S_vn) is distinguished by the presence of a blunt evagination, which in B. oleracea wraps around and lies within shallow furrows on the vegetative nucleus and in B. campestris can penetrate through internal enclaves of the vegetative nucleus. This sperm cell contains more mitochondria in both species than the second sperm cell (S_ua). This latter cell is linked to the first by a common cell junction with the S _vn, but is not associated with the vegetative nucleus and lacks a cellular evagination. Such differences are indicative of a system of cytoplasmic heterospermy in which sperm cells possess significantly different quantities of mitochondria.Abbreviations mtDNA mitochondrial DNA - S_ua sperm cell unassociated with the vegetative nucleus - S_vn Sperm cell physically associated with the vegetative nucleus     

Ultrastructure of the mature spermatozoon of the musky rat-kangaroo, Hypsiprymnodon moschatus (Potoroidae: Marsupialia)

It is currently accepted that Hypsiprymnodon moschatus is a basal macropod, retaining several primitive features from the ancestral phalangeroid that gave rise both to modern possums and macropods. Sperm ultrastructure is frequently found to provide informative characters for phylogenetic analysis as these features are not strongly selected for and are thus unlikely to be confounded by effects such as convergence. Caudal epididymal biopsies were taken from two male H. moschatus and prepared for transmission and scanning electron microscopy in order to study mature spermatozoan ultrastructure. Within the diprotodont group, several features were found to be unique to H. moschatus. These were an unusual acrosome covering nearly 100% of the dorsal nuclear surface, a midpiece fibre network which is loose, indistinct and extends to the anterior‐most aspect of the midpiece, a nucleus that is very streamlined, while the principal piece is comparatively short, and a mitochondrial helix and annulus which are similar to those of dasyurids. Also reported is the presence of a fibrous network in the connecting piece, not previously reported for any marsupial.     

Preservation of the chondrocyte's pericellular matrix improves cell‐induced cartilage formation

The extracellular matrix surrounding chondrocytes within a chondron is likely to affect the metabolic activity of these cells. In this study we investigated this by analyzing protein synthesis by intact chondrons obtained from different types of cartilage and compared this with chondrocytes. Chondrons and chondrocytes from goats from different cartilage sources (articular cartilage, nucleus pulposus, and annulus fibrosus) were cultured for 0, 7, 18, and 25 days in alginate beads. Real‐time polymerase chain reaction analyses indicated that the gene expression of Col2a1 was consistently higher by the chondrons compared with the chondrocytes and the Col1a1 gene expression was consistently lower. Western blotting revealed that Type II collagen extracted from the chondrons was cross‐linked. No Type I collagen could be extracted. The amount of proteoglycans was higher for the chondrons from articular cartilage and nucleus pulposus compared with the chondrocytes, but no differences were found between chondrons and chondrocytes from annulus fibrosus. The expression of both Mmp2 and Mmp9 was higher by the chondrocytes from articular cartilage and nucleus pulposus compared with the chondrons, whereas no differences were found with the annulus fibrosus cells. Gene expression of Mmp13 increased strongly by the chondrocytes (>50‐fold), but not by the chondrons. Taken together, our data suggest that preserving the pericellular matrix has a positive effect on cell‐induced cartilage production. J. Cell. Biochem. 110: 260–271, 2010. © 2010 Wiley‐Liss, Inc.