高濃度鈣離子脅迫對(duì)褐牙鲆幼魚鰓黏液細(xì)胞數(shù)量、超微結(jié)構(gòu)及分泌方式的影響

張靈燕,張秀梅＊＊,姜 明

(中國海洋大學(xué)1.海水養(yǎng)殖教育部重點(diǎn)實(shí)驗(yàn)室;2.海洋生命學(xué)院,山東青島266003)

高濃度鈣離子脅迫對(duì)褐牙鲆幼魚鰓黏液細(xì)胞數(shù)量、超微結(jié)構(gòu)及分泌方式的影響

張靈燕1,張秀梅1＊＊,姜 明2

(中國海洋大學(xué)1.海水養(yǎng)殖教育部重點(diǎn)實(shí)驗(yàn)室;2.海洋生命學(xué)院,山東青島266003)

利用光學(xué)顯微鏡和透射電子顯微鏡,研究了高濃度鈣離子(37.5±0.1)mmol/L脅迫對(duì)褐牙鲆(Paralichthys olivaceus)幼魚鰓黏液細(xì)胞數(shù)量、超微結(jié)構(gòu)及分泌方式的影響。結(jié)果表明,高濃度鈣離子組實(shí)驗(yàn)魚鰓弓黏液細(xì)胞的數(shù)量與對(duì)照組無顯著差異(P>0.05);高濃度鈣離子組和對(duì)照組實(shí)驗(yàn)魚鰓絲黏液細(xì)胞的超微結(jié)構(gòu)相同,未成熟黏液細(xì)胞呈棒狀,具發(fā)達(dá)的高爾基體和粗面內(nèi)質(zhì)網(wǎng),細(xì)胞核近圓形,位于細(xì)胞底部,細(xì)胞頂膜在鰓上皮組織表面凹陷形成分泌腔,成熟黏液細(xì)胞體積較大,呈圓形,黏液顆粒排列緊密,充滿整個(gè)細(xì)胞,基質(zhì)密度大,細(xì)胞器位于細(xì)胞底部,細(xì)胞核形狀不規(guī)則;高濃度鈣離子組和對(duì)照組實(shí)驗(yàn)魚鰓絲黏液細(xì)胞的分泌方式相同,均為頂漿分泌,但高濃度鈣離子組實(shí)驗(yàn)魚黏液細(xì)胞分泌活動(dòng)旺盛,大量黏液正在向胞外排放,而對(duì)照組黏液細(xì)胞的黏液分泌量較少。研究認(rèn)為,褐牙鲆幼魚對(duì)高濃度鈣離子脅迫具有較強(qiáng)的耐受能力。

Ca2+;褐牙鲆;黏液細(xì)胞;顯微結(jié)構(gòu);超微結(jié)構(gòu)

Ca2+是自然海水的重要組成部分,對(duì)魚類的神經(jīng)元興奮性、肌肉收縮、細(xì)胞滲透性、細(xì)胞分化、激素釋放和骨組織的礦物化等生理作用均具有重要影響[1]。已有研究表明,水中鈣離子濃度是影響魚體黏液細(xì)胞分泌和數(shù)量變化的重要環(huán)境因子[2]。研究發(fā)現(xiàn),低濃度鈣離子能夠顯著誘導(dǎo)莫桑比克羅非魚(S arotherodon mossambicus)體表上皮組織中黏液細(xì)胞的增殖[3-4]。另據(jù)研究表明,低濃度鈣離子能夠刺激莫桑比克羅非魚、革胡子鯰(Clarias lazera)和虹鱒(S almon gairdnert)黏液中鈣調(diào)蛋白含量的顯著增加,從而增強(qiáng)魚體表皮的滲透調(diào)節(jié)能力[5]。但關(guān)于高濃度鈣離子脅迫對(duì)魚體黏液細(xì)胞的影響,目前尚未見報(bào)道。

黏液細(xì)胞(Mucous cells)是普遍存在于魚類上皮中的1種腺體細(xì)胞,主要分布在魚體皮膚、鰓及消化道的上皮中,其主要功能是分泌黏液,進(jìn)而參與機(jī)體的呼吸、攝食、排泄、滲透調(diào)節(jié)和免疫等生命活動(dòng)[6-7]。當(dāng)魚體受到外界脅迫時(shí),其體表黏液細(xì)胞就會(huì)分泌大量黏液,保護(hù)魚體免受外界損傷[8-10],因此黏液細(xì)胞的分泌方式與魚體應(yīng)對(duì)外界環(huán)境變化的能力密切相關(guān)。本研究以褐牙鲆(Paralichthys olivaceus)幼魚為實(shí)驗(yàn)對(duì)象,研究了高濃度鈣離子脅迫對(duì)褐牙鲆幼魚鰓黏液細(xì)胞數(shù)量、超微結(jié)構(gòu)及分泌方式的影響,以期為了解褐牙鲆幼魚對(duì)高濃度鈣離子脅迫的耐受能力及改善養(yǎng)殖環(huán)境提供參考。

1 材料與方法

1.1 實(shí)驗(yàn)材料

實(shí)驗(yàn)用褐牙鲆幼魚購于山東文登小觀鎮(zhèn)養(yǎng)殖場(chǎng),運(yùn)回后置于實(shí)驗(yàn)室水槽(280 cm×175 cm×150 cm)中暫養(yǎng)2周。暫養(yǎng)期間,水溫(18±0.3)℃,鹽度30±0.5, pH=7.9±0.2,自然海水的主要離子濃度(mmol/L): Ca2+:9.7,Mg2+:49.4,SO2-4:25.4,Na+:415.2, Cl-:443.1,K+:11.3,連續(xù)充氣,日換水率100%,每日06··00和18··00各投喂1次牙鲆專用顆粒配合飼料,日投餌量為幼魚體質(zhì)量的3%～4%,投喂后2 h及時(shí)吸除殘餌及糞便。

1.2 實(shí)驗(yàn)設(shè)計(jì)

實(shí)驗(yàn)設(shè)定2個(gè)處理組:常規(guī)人工海水組(對(duì)照組)和高濃度鈣離子人工海水組。常規(guī)人工海水使用曝氣的自來水和海水素(青島海大通用海水素有限公司生產(chǎn))配制,主要離子濃度(mmol/L):Ca2+:10.3, Mg2+:51.1,SO2-4:24.9,Na+:425.9,Cl-:431.8, K+:12.1;高濃度鈣離子人工海水使用曝氣的自來水和無鈣海水素配制,通過添加CaCl2分析純調(diào)節(jié)Ca2+的濃度為(37.5±0.1)mmol/L,其他離子濃度與常規(guī)人工海水組相同,2個(gè)實(shí)驗(yàn)組鹽度均為30±0.5,每日06··00和18··00測(cè)定Ca2+含量,出現(xiàn)波動(dòng),及時(shí)調(diào)節(jié)。

暫養(yǎng)結(jié)束后,隨機(jī)選擇50尾大小一致、健康活潑的褐牙鲆幼魚(體長(160±40)mm,體質(zhì)量(45±3) g),直接將實(shí)驗(yàn)魚放入實(shí)驗(yàn)水槽內(nèi),每組25尾。實(shí)驗(yàn)期間的養(yǎng)殖管理與暫養(yǎng)期間完全相同。實(shí)驗(yàn)的取樣時(shí)間為6,72,144和216 h。每次取樣時(shí)從實(shí)驗(yàn)水槽中隨機(jī)選取5尾幼魚,取兩側(cè)鰓絲。

1.3 樣品測(cè)定

1.3.1 組織切片的制作及鰓弓黏液細(xì)胞數(shù)量的計(jì)算在實(shí)驗(yàn)第72,144和216 h時(shí),取對(duì)照組和高濃度鈣離子組實(shí)驗(yàn)魚鰓組織的鰓弓部分,切成0.5 cm3的組織塊,用Bouin氏液固定24 h,然后用70%酒精沖洗;梯度乙醇脫水;石蠟包埋;切片厚度為4～5μm;蘇木精-伊紅染色;中性樹膠封片;用Nikon,Eclipse LV100POL顯微鏡觀察并進(jìn)行顯微拍照。黏液細(xì)胞數(shù)量的計(jì)算:使用Image J測(cè)量軟件對(duì)鰓弓的長度進(jìn)行測(cè)量,計(jì)算鰓弓單位長度內(nèi)黏液細(xì)胞的個(gè)數(shù)(個(gè)/mm),每尾幼魚觀察10個(gè)視野(×400)內(nèi)鰓弓黏液細(xì)胞的數(shù)量,即每個(gè)實(shí)驗(yàn)組統(tǒng)計(jì)50個(gè)視野內(nèi)黏液細(xì)胞的平均個(gè)數(shù)。

1.3.2 透射電鏡的制作 實(shí)驗(yàn)發(fā)現(xiàn),將實(shí)驗(yàn)魚放入高濃度鈣離子水體后,實(shí)驗(yàn)魚體表黏液分泌量在3～7 h異常增加。為觀察前期應(yīng)激階段實(shí)驗(yàn)魚黏液細(xì)胞超微結(jié)構(gòu)的變化,在實(shí)驗(yàn)第6 h時(shí)(即前期應(yīng)激階段,魚體表黏液分泌旺盛期),取對(duì)照組和高濃度鈣離子組實(shí)驗(yàn)魚鰓組織的鰓絲部分,切成0.5 mm3的組織塊,置于5%的戊二醛溶液中,4℃下固定一周。用1%鋨酸溶液固定1 h;梯度乙醇脫水;Epon-812滲透和包埋;經(jīng)半薄切片定位,用L KB超薄切片機(jī)對(duì)鰓小葉進(jìn)行超薄切片;常規(guī)電鏡切片染色;用日產(chǎn)Hatachi,H-7000型電子顯微鏡觀察并拍照。

1.4 數(shù)據(jù)分析

數(shù)據(jù)統(tǒng)計(jì)分析采用SPSS 11.5軟件,用t-檢驗(yàn)分析高濃度鈣離子組與對(duì)照組鰓弓黏液細(xì)胞數(shù)量之間的差異顯著性(P<0.05)。

2 觀察結(jié)果

2.1 鰓弓黏液細(xì)胞數(shù)量的顯微觀察

在實(shí)驗(yàn)第72,144和216 h時(shí),分別對(duì)對(duì)照組和高濃度鈣離子組中鰓弓黏液細(xì)胞的數(shù)量進(jìn)行了統(tǒng)計(jì)分析,見圖1。由圖1可以看出,實(shí)驗(yàn)期間,對(duì)照組和高濃度鈣離子組鰓弓黏液細(xì)胞數(shù)量變化穩(wěn)定,2組間無顯著差異(P >0.05)。顯微觀察結(jié)果表明,對(duì)照組和高濃度鈣離子組鰓弓表皮內(nèi)并排分布著大量黏液細(xì)胞(見圖版-Ⅰ)。

圖版ⅠⅠ-1.常規(guī)人工海水組,鰓弓黏液細(xì)胞的數(shù)量;Ⅰ-2.高濃度鈣離子人工海水組,72 h時(shí)鰓弓黏液細(xì)胞的數(shù)量;Ⅰ-3.高濃度鈣離子人工海水組,144 h時(shí)鰓弓黏液細(xì)胞的數(shù)量;Ⅰ-4.高濃度鈣離子人工海水組,216 h時(shí)鰓弓黏液細(xì)胞的數(shù)量MC:黏液細(xì)胞;B:血管道;cart:軟骨Explanation of PlatesⅠⅠ-1.Normal artificial seawater,the number of musous cells in gill arch;Ⅰ-2.High calcium concentration artificial seawater,the number of musous cells in gill arch,72 h;Ⅰ-3.High calcium concentration artificial seawater,the number of musous cells in gill arch,144 h;Ⅰ-4.High calcium concentration artificial seawater,the number of musous cells in gill arch,216 hMC:mucous cell;B:blood channel;cart:cartilage

圖版ⅡⅡ-1.鰓絲未成熟黏液細(xì)胞的完整結(jié)構(gòu)標(biāo)尺=1μm;Ⅱ-2.鰓絲成熟黏液細(xì)胞的完整結(jié)構(gòu)標(biāo)尺=2μm;Ⅱ-3.常規(guī)人工海水組,鰓絲黏液細(xì)胞排放初期標(biāo)尺=2μm;Ⅱ-4.高濃度鈣離子人工海水組,鰓絲黏液細(xì)胞排放初期標(biāo)尺=1μm;Ⅱ-5.高濃度鈣離子人工海水組,鰓絲黏液細(xì)胞排放末期標(biāo)尺=1μm;Ⅱ-6.高濃度鈣離子人工海水組,鰓絲黏液細(xì)胞排放末期細(xì)胞內(nèi)空泡結(jié)構(gòu)(V)的高倍圖像標(biāo)尺=3μmG:高爾基體;RER:粗面內(nèi)質(zhì)網(wǎng);C:分泌腔;N:細(xì)胞核;PVC:扁平上皮細(xì)胞;M:黏液;V:空泡;白色星號(hào):黏液顆粒PlatesⅡⅡ-1.The integrity structure of the immature mucous cell in gill filament,Scale bar=1μm;Ⅱ-2.The integrity structure of the well-developed mucous cell in gill filament,Scale bar=2μm;Ⅱ-3.Normal artificial seawater,the early stage of the secretory mucous cell in gill filament,Scale bar=2μm;Ⅱ-4.High calcium concentration artificial seawater,the early stage of the secretory mucous cell in gill filament,Scale bar=1μm;Ⅱ-5.High calcium concentration artificial seawater,the final stage of the secretory mucous cell in gill filament,Scale bar=1μm;Ⅱ-6.High calcium concentration artificial seawater,the high magnification image of vacuoles(V)in the final stage of the secretory mucous cell in gill filament,Scale bar=3μmG:Golgi apparatus;RER:rough endoplasmic reticulum;C:prominent crypt;N:nucleus;PVC:pavement cell;M:mucus;V:vacuole;white asterisk:mucous granules

圖1 高濃度鈣離子脅迫對(duì)褐牙鲆幼魚鰓弓黏液細(xì)胞數(shù)量(個(gè)/mm)的影響Fig.1 Effects of high calcium concentration stress on number of mucous cells(number/millimetre)in gill arch of juvenileP.olivaceus

2.2 鰓絲黏液細(xì)胞的超微結(jié)構(gòu)

電鏡觀察結(jié)果顯示,黏液細(xì)胞主要位于鰓弓和鰓絲上皮組織內(nèi),在鰓絲上皮內(nèi)的黏液細(xì)胞通常分布在氯細(xì)胞周圍。對(duì)照組與高濃度鈣離子組鰓絲電鏡切片中均可觀察到未成熟與成熟黏液細(xì)胞,其超微結(jié)構(gòu)觀察結(jié)果如下:

2.2.1 未成熟黏液細(xì)胞 電鏡觀察結(jié)果表明,對(duì)照組與高濃度鈣離子組未成熟黏液細(xì)胞的超微結(jié)構(gòu)相同。未成熟黏液細(xì)胞,體積較小,呈棒狀;少數(shù)黏液顆粒分布在細(xì)胞頂部;細(xì)胞核位于基底部,核體較大,呈圓形,異染色質(zhì)主要沿核膜邊緣聚集,未觀察到核仁;高爾基體和粗面內(nèi)質(zhì)網(wǎng)發(fā)達(dá),高爾基體凹面可見分泌小泡,粗面內(nèi)質(zhì)網(wǎng)沿膜邊緣分布;細(xì)胞頂膜在鰓組織表面凹陷形成分泌腔(見圖版Ⅱ-1)。

2.2.2 成熟黏液細(xì)胞 電鏡觀察結(jié)果表明,對(duì)照組與高濃度鈣離子組成熟黏液細(xì)胞的超微結(jié)構(gòu)相同。成熟黏液細(xì)胞,體積較大,呈圓形;黏液顆粒排列緊密,充滿整個(gè)細(xì)胞;細(xì)胞頂膜平滑;基質(zhì)密度大;細(xì)胞器位于細(xì)胞底部;細(xì)胞核形狀不規(guī)則,未觀察到核仁(見圖版Ⅱ-2)。

2.3 鰓絲黏液細(xì)胞分泌方式的超微觀察

實(shí)驗(yàn)發(fā)現(xiàn),高濃度鈣離子組實(shí)驗(yàn)魚反應(yīng)劇烈,進(jìn)入實(shí)驗(yàn)水體3～7 h時(shí),其體表分泌大量黏液,在魚體表皮形成厚厚的黏液層,電鏡結(jié)果顯示,高濃度鈣離子組實(shí)驗(yàn)魚鰓絲黏液細(xì)胞分泌活動(dòng)旺盛,大量黏液正在向胞外排放,而對(duì)照組黏液細(xì)胞的分泌量較少。高濃度鈣離子組鰓黏液細(xì)胞的分泌方式與對(duì)照組相同,均為頂漿分泌。黏液細(xì)胞排放初期,細(xì)胞頂膜破裂,頂膜處幾個(gè)相鄰的黏液顆粒首先融合破裂并在胞內(nèi)釋放黏液,通過頂膜的開口將黏液排出體外,殘留的黏液顆粒膜在胞內(nèi)形成空泡結(jié)構(gòu)(見圖版Ⅱ-3,4)。黏液顆粒的排放按照一定的順序進(jìn)行,即首先排放細(xì)胞頂部和中心的黏液顆粒,接著排放細(xì)胞周邊的黏液顆粒,最后排放細(xì)胞底部的黏液顆粒。黏液細(xì)胞排放末期,分泌腔擴(kuò)大,胞內(nèi)含有大量黏液和空泡結(jié)構(gòu)(見圖版Ⅱ-5,6)。

3 討論

莫桑比克羅非魚在適應(yīng)海水的過程中,魚體表皮黏液細(xì)胞的數(shù)量顯著下降,研究發(fā)現(xiàn),海水中的鈣離子是影響?zhàn)ひ杭?xì)胞數(shù)量變化的主要環(huán)境因子,與水體滲透壓和高濃度的NaCl等因素?zé)o關(guān),降低海水中鈣離子濃度則能夠刺激魚體表皮黏液細(xì)胞的增殖[2-4]。研究證明,低濃度的鈣離子能夠刺激魚體泌乳刺激素的分泌,從而誘導(dǎo)黏液細(xì)胞的增殖;高濃度的鈣離子能夠抑制魚體泌乳刺激素的分泌,從而抑制黏液細(xì)胞的增殖[4,11]。本研究結(jié)果表明,高濃度鈣離子脅迫216 h,褐牙鲆鰓弓黏液細(xì)胞的數(shù)量無顯著變化(P>0.05)。分析認(rèn)為,褐牙鲆具有較強(qiáng)的調(diào)節(jié)高濃度鈣離子的能力,無需改變鰓弓黏液細(xì)胞的數(shù)量,便可應(yīng)對(duì)外界環(huán)境中鈣離子濃度的變化,同時(shí)也說明不同魚類對(duì)鈣離子濃度的調(diào)節(jié)能力不同。

當(dāng)魚體遭遇脅迫時(shí),體表就會(huì)迅速分泌大量黏液,以應(yīng)對(duì)外界環(huán)境的變化。電鏡觀察結(jié)果顯示,實(shí)驗(yàn)魚鰓絲黏液細(xì)胞的頂膜暴露在外面,可與外界環(huán)境直接接觸,有利于黏液細(xì)胞對(duì)外界環(huán)境的變化及時(shí)做出應(yīng)激反應(yīng)。本實(shí)驗(yàn)觀察到,在接觸高濃度鈣離子人工海水初期,褐牙鲆反應(yīng)劇烈,魚體出現(xiàn)抽搐現(xiàn)象,體表形成厚厚的黏液層,減少了魚體對(duì)海水離子的通透性,是魚體自我保護(hù)的重要機(jī)制。但電鏡觀察發(fā)現(xiàn),高濃度鈣離子脅迫對(duì)褐牙鲆幼魚鰓絲黏液細(xì)胞的超微結(jié)構(gòu)無顯著影響。然而研究原油對(duì)斑尾小鲃(Puntius sophore)鰓上皮黏液細(xì)胞的毒性效應(yīng)時(shí)發(fā)現(xiàn),在致死劑量下暴露12 h,黏液細(xì)胞退化分解[12]。這說明不同脅迫條件及脅迫程度對(duì)魚體黏液細(xì)胞超微結(jié)構(gòu)造成的影響不同。

魚體黏液細(xì)胞在脅迫條件下能夠迅速排放大量黏液,因此其黏液的分泌方式與魚體適應(yīng)外界環(huán)境的能力密切相關(guān)。魚類黏液細(xì)胞主要有3種分泌方式:局漿分泌(Merocrine secretion)[13]、頂漿分泌(Apocrine secretion)[14-16]和全漿分泌(Holocrine secretion)[17-18]。研究表明,在正常情況下,哺乳動(dòng)物腸道等黏液細(xì)胞一般采用局漿分泌持續(xù)分泌少量黏液,滿足機(jī)體的正常需要[19],當(dāng)受到外界刺激時(shí),機(jī)體黏液細(xì)胞則通過頂漿分泌或全漿分泌迅速分泌大量黏液,滿足機(jī)體的應(yīng)激需求[20]。本研究結(jié)果表明,褐牙鲆幼魚鰓絲黏液細(xì)胞在高濃度鈣離子人工海水和常規(guī)人工海水中的分泌方式相同,均為頂漿分泌,但在高濃度鈣離子脅迫條件下實(shí)驗(yàn)魚鰓黏液細(xì)胞的分泌活動(dòng)旺盛,大量黏液正在向胞外排放,且其分泌特點(diǎn)與其他魚類的頂漿分泌不完全相同[14-16]。主要表現(xiàn)為:(1)黏液的排放并未僅局限于細(xì)胞的頂部,分泌腔隨著黏液的不斷排出而逐漸擴(kuò)大;(2)黏液顆粒直接在胞內(nèi)破裂并釋放黏液,無需向細(xì)胞頂部移動(dòng),節(jié)省了黏液排放的時(shí)間;(3)黏液排放末期大量空泡堆積在胞內(nèi),細(xì)胞有收縮復(fù)原現(xiàn)象,這與哺乳動(dòng)物腸黏液細(xì)胞分泌規(guī)律相似[20],因此作者推測(cè),胞內(nèi)殘留的空泡可能參與黏液細(xì)胞頂膜的修復(fù); (4)黏液顆粒的排放按照一定順序進(jìn)行。根據(jù)不同分泌時(shí)相的電鏡觀察,作者建立了褐牙鲆幼魚鰓絲黏液細(xì)胞黏液排放過程模式圖(見圖2)。分析認(rèn)為,褐牙鲆鰓絲黏液細(xì)胞的分泌特點(diǎn)與其較強(qiáng)的環(huán)境適應(yīng)能力相關(guān),但關(guān)于其他鲆鰈類是否具有相同的分泌特點(diǎn)有待于進(jìn)一步研究。

圖2 褐牙鲆幼魚鰓絲黏液細(xì)胞黏液排放過程模式圖Fig.2 Schematic representation of secretory process of the mucous cells in the gill filament of juvenileP.olivaceus

鲆鰈類是近岸底棲性魚類,鹽度、溶氧、p H、海水中離子組成及濃度變化等是影響其生長和成活的重要環(huán)境因子,對(duì)此已有許多研究報(bào)道,主要集中在生長、生理調(diào)節(jié)、免疫應(yīng)答等方面[21-23],而環(huán)境脅迫條件下魚體內(nèi)化學(xué)物質(zhì)的形成及排放過程等方面的研究相對(duì)薄弱。本研究結(jié)果表明,高濃度鈣離子脅迫對(duì)鰓弓黏液細(xì)胞的數(shù)量、超微結(jié)構(gòu)無顯著影響,黏液細(xì)胞均以頂漿分泌方式分泌黏液,但高濃度鈣離子組實(shí)驗(yàn)魚黏液細(xì)胞分泌旺盛,大量黏液向體外排放,使魚體表面形成一個(gè)保護(hù)層,從而增加了褐牙鲆對(duì)高濃度鈣離子脅迫的耐受能力。因此,深入研究褐牙鲆鰓黏液細(xì)胞黏液的形成及排放規(guī)律,對(duì)了解鲆鰈類滲透調(diào)節(jié)機(jī)制和魚體防御機(jī)能具有重要意義。

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Abstract: The effects of high calcium concentration stress on number,ultrastructure and secretory process of mucous cells in the gill of juvenileParalichthys olivaceuswere investigated by light microscope and transmission electron microscopy(TEM).The results showed that there was no significant difference in the number of mucous cells in gill arch between high calcium concentration group and control group(P >0.05).No difference in untrastructure of mucous cells in gill filament between the two experimental groups was observerd.Immature mucous cell was club-shaped and contained developed Golgi apparatus and rough endoplasmic reticulum.The nucleus was round and located in the base of the cell and the prominent crypt was curved in the surface of the gill epithelial tissue.Well-developed mucous cell was round and bigger than immature cell.The cell was filled with mucous granules and the whole organelles were compressed in the basal part of the cell.The cytoplasmic regions were electron dense and the nucleus was irregular.The secretory process of mucous cells in gill filament was same between the two experimental groups,belonging to apocrine secretion.However,the secretory activity of mucous cells was vigorous with discharging massive mucus in high calcium concentration group,while it’s weak in control group. The results indicated that juvenileP.olivaceushad strong tolerance of high calcium concentration stress.

Key words: Ca2+;Paralichthys olivaceus;mucous cell;microstructure;ultrastructure

責(zé)任編輯 于 衛(wèi)

Effects of High Calcium Concentration Stress on Number,Ultrastructure and Secretion of Mucous Cells in Juvenile Paralichthys olivaceus Gill

ZHAN G Ling-Yan1,ZHAN G Xiu-Mei1,J IANG Ming2
(Ocean University of China 1.The Key Laboratory of Mariculture,Ministry of Education;2.Colloge of Marine Life Sciences,Qingdao 266003,China)

S917.4

A

1672-5174(2010)09Ⅱ-076-07

國家科技支撐計(jì)劃課題(2006BAD09A15);國家自然科學(xué)基金項(xiàng)目(30600462)資助

2009-09-14;

2010-04-13

張靈燕(1983-),女,碩士生。E-mail:zhanglingyan2007@yahoo.com.cn

E-mail:gaozhang@ouc.edu.cn